* Set dimensions properly of images on initialization.

Fix for #3203

Image nodes were assigned the default size on initialization, leading to very compressed images.
This fix adjusts the default size as soon as the images used have been loaded.

The approach for dealing with this has been adapted from `CircularImage`.

* Fixed tabs

* Consolidated common code for drawing in nodes

* Consolidated updateBoundingBox(), default version

* Setting bounding box margin in separate method

Fixes a race condition that set an item's group to be set to undefined
if it was dropped and then dragged again without a redraw happening in
between.

The returned node id's were exactly the wrong way around;
'to' returned the parents, 'from' returned the children.

This fix swaps the tests for determining which to return.

* Fix for timeline TimeStep.roundToMinor - resolving issue #3105

* Adding some tests for TimeStep

Code in the `_line()` of the sibling Bezier edge types was either extremely similar or identical.
The Bezier drawing code has been consolidated in a single method in the parent class.

This method is needlessly complicated. Code has been adjusted to better show the intent.

In addition:
- reuse of variables already present, notably `dx` and `dy`
- put recurring code fragments into local variables
- removed second conditions in constructs of the form `if (condition) ... else if (!conditioni) ...`

The refactoring can be taken further, but it would change the conditional flow, which would complicate reviewing.
The current changes highlight the similarities between the code blocks.

* Consolidate code for determining the pixel ratio

* - Removed local param  'pixerRatio' from CanvasRenderer. Now only canvas.pixelRatio is used.
- consolidated ctx.transform() calls in Canvas
- Added/edited commenting (also TODO's)
- Added Canvas.getContext()

Fix for #3036

Option `smooth.type: dynamic` is not allowed for hierarchical layouts.
This was handled properly for the main options, but not for the node-specific options.

Options within node instances arei now checked for `smooth.type: dynamic` and replaced
by `horizontal` or `vertical`. The implementation adds listener `_adjustEdgesForHierarchicalLayout`
in `LayoutHandler`. This listener must be activated every time noder- specific options might change.
This happens in the logical places within `EdgeHandler`.

* clusters in hierarchical working for sortorder 'hubsize'

* Code cleanup

* Protect Network from zero and negative mass values

Fix for #3133

Option-field 'node.mass` must be >= 0.
Checks have been added at the nodes level, for both nodes-global and nodes specific options.
In addition, an internal check has been added for `NodeHandler.defaultOptions`.

The documentation has been adjusted for this change.

* Fix whitespace

* Prevent crashes from invalid id's in `Clustering.findNode()`

Fix for #3163

- Added safeguards in said method, to prevent exceptions happening when invalid id's are passed in.
- Adjusted documentation for said method
- Added notes to flag unused methods in `Clustering.js`

* Removed incorrect NOTE-comments from methods that are indeed used

Fix for #3106

Event `stabilizationProgress` is now always sent for iteration 0 and for the very last stabilization iteration.

* First working version of new class DataGroup.

* Adjustments for review - done all points except last

* DRY distinct values, clean up sort code

* Added missing @param's to comments in DataGroup

Call on issue brought to light by #2990.

`ctx` should not be passed as a parameter to the call - not needed and not conform to documentation.
Also cleaned up the calling code to remove the double `fontOptions.chooser()` call.

* Properly handle newline escape sequences in strings for DOT

* Adjust comments in code

* First save after refactoring

* Fixes after testing

* Final changes

Currently `align` is only available as a global timeline configuration
option. This change allows overriding alignment on a per-item basis.

* Fix selection nodes so that option selectConnectedEdges works as expected

* Using instance var select instead of local var in Edge.drawLabel()

* Changed order of (de)select events for network

* Fixed parameters to _generateClickEvent() to be compatible with previous.

* Added param 'direction' to Network.getConnectedNodes()

* Redo commit - Network.js does not need to change

Awesome work! Thanks again!

* Add support for multiple class names in utils add/remove class methods.
Reset subgroup heights in resetSubgroups method.

* Adjust to better process class names

* Add 'showTooltips' timeline option

* Only show timeline popup if option showTooltips is true

* Add 'showTooltips' option to timeline docs

* Add tooltips disabled timeline example

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Add .travis.yml file

* Add experiment travis code

* Fix react example

* Improve redraw performance by not restacking non-visible groups (related to #2835)

* only restack necessary groups on redraw (related to #2835)

* replacing all ES6 imports with CJS require calls
resolves #2934
used the following regex to apply the changes in lib:
s/import\s+(\w+)\s+from\s+(.*);\s*$/var $1 = require($2).default;/
s/import\s+(\w+)\s+from\s+(.*)\s*$/var $1 = require($2).default;/

* cleaning up inconsistencies

* Add warnings and errors for image loading

* Fixes and commenting for image loading

* Fix typo

* Small fixes due to review

Sorry for the delay on this... It took me a while to confirm this PR again. I don;t know why I didn't merge it at the time I reviewed it. Looks great to me!

* mouseup and mousedown events

* Fix error

* CachedImage with preredendered zoom images; first working version.

* Fixes for missing images and usage brokenImage.

* Remove unused method

* Added height member of CachedImage, note about svg's

* Refactor propagateFonts(), first working version. Default font  for 'mono' is now 'monospace'

* Tested and cleaned up refactoring changes

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Add .travis.yml file

* Add experiment travis code

* Fix react example

* Fix item click and doubleclick

* Remove new empty line

* Return id of item tapped

* Fix comments from Review

* Add missing semicolon

* Add Gitter badge (#2179)

* do not generate source-maps in distribution version

* add 'dist' folder for deployment

* added Badges

* added codeclimate badge

* added @Tooa to the support team

* added badges from isitmaintained.com (#2517)

* do not ignore dist and test folders in master

* generated dist files for v4.18.0

* generated dist files for v4.18.1

* Cheap fix for bug #2795

* Update to PR #2826 to use newline format

* changed to v4.18.1-SNAPSHOT

* chore(docs): general improvements (#2652)

* removed NOTICE file

* updated license date range to include 2017

* chore(docs): updated support team members

* chore: updated dependencies and devDependencies (#2649)

* Fixes instanceof Object statements for objects from other windows and iFrames. (#2631)

* Replaces instanceof Object checks with typeof to prevent cross tab issues.

* Adds missing space.

* chore: removed google-analytics from all examples (#2670)

* chore(docs): Add note that PRs should be submitted against the `develop` branch (#2623)

Related to: https://github.com/almende/vis/pull/2618
Related to: https://github.com/almende/vis/pull/2620

* feat(timeline): Change setCustomTimeTitle title parameter to be a string or a function (#2611)

* change setCustomTimeTitle title parameter, Now could be an string or a function
* Fixed indent and spacing

* feat(timeline): refactor tooltip to only use one dom-element (#2662)

* feat(network): Allow for image nodes to have a selected or broken image (#2601)

* feat(tests): run mocha tests in travis ci (#2687)

* Added showX(YZ)Axis options to Graph3d (#2686)

* Added showX(YZ)Axis to Graph3d

* Added show_Axis options to docs and playground example

* Resolved merge conflict

* Added show_Axis options to docs and playground example

* fix(build): use babel version compatible with webpack@1.14 (#2693)

fixes #2685

* feat(docs): use babel preset2015 for custom builds (#2678)

* add link to a mentioned example (#2709)

* chore(lint): added support for eslint (#2695)

* Trivial typo fix in how_to_help doc. (#2714)

* fix(timeline): #2598 Flickering onUpdateTimeTooltip (#2702)

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix react example
* Add animation to onUpdateTooltip

* fix(timeline): #778 Tooltip does not work with background items in timeline (#2703)

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix react example
* Make items z-index default to 1

* Add initial tests for Timeline PointItem (#2716)

* fix(timeline): #2679 TypeError: Cannot read property 'hasOwnProperty' of null (#2735)

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix react example
* Fix bug in item editable

* feat(timeline): #2647 Dynamic rolling mode option (#2705)

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix react example
* Add toggleRollingMode option
* Update docs with toggleRollingMode option

* fixes timestep next issue (#2732)

* feat(timeline): added new locales for french and espanol (#2723)

* Fix eslint problem on Travis. (#2744)

* fix: Range.js "event" is undeclared (#2749)

* fix(timeline): #2720 Problems with option editable (#2743)

Clean up and centralise edit status for Timeline Items.

* feat(network): Improve the performance of the network layout engine (#2729)

* Improve the performance of the network layout engine

Short-cut the execution of a number of methods in LayoutEngine to make them
handle highly-connected graphs better.

* Demonstrations of layouts of large networks

* Added support to supply an end to bar charts to have them scale (#2760)

* Added support to supply an X2 to bar charts to have them scale

* Fixed graph2d stacking issue.  It no longer takes into account hidden items

* Changed x2 to end per recommendation and added this to the docs

* Initial tests for timeline ItemSet. (#2750)

Somewhat more complicated setup, associated with the need for a real window.

* [Timeline] Modify redraw logic to treat scroll as needing restack. (#2774)

This addresses #1982 and #1417.

It possibly reduces performance, but correctness seems better.

* fix(timeline): #2672 Item events original event (#2704)

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Add .travis.yml file

* Add experiment travis code

* Fix react example

* Fix events returned from mouse events

* Fix example

* Rename censor to stringifyObject in example

* [timeline] Update examples to use ISOString format. (#2791)

Resolves #2790

* [timeline] Update serialization example to use ISOString dates. (#2789)

Resolves #2696

* added github templates for issues and pull-requests (#2787)

fixes #2418

* feat(timeline): Add item data as argument to the template function (#2799)

* Fix regression introduced in #2743. (#2796)

* Fix for issue #2536 (#2803)

* Fix for issue #2536

* Adjusted documentation for fix.

* Adjustments due to review

* Grrrrr whitespace

* Fixed Travis issue

* Cheap fix for bug #2795

* Update to PR #2826 to use newline format

* Update to gitignore to reflect changes on remote

* clean dist folder

* Local gitignore update

* Just a first example file for the week scale feature

* Allowing sourcemap creation

* Initial (non-functional) commit to ensure we insert code at the right places (check TODOs)

* Functional, not bug-free version which works with locale aware week numbers.

* Locale-aware implementation and simplified major labels to a full year

* Trying to make the major labels show the correct start date

* Working implementation of week numbers using localization.

* removing development leftovers

* Updated package.json

* Reintagrate package.json from accidental deletion

* Updates for package.json

* Fixing package.json

* Integrate the week numbers feature in the documentation.

* Reverting local changes to .gitignore

* Reverting local changes

* Extending examples to cover the case when 1st day of week and 1st day of month align; Fixing display bug so that week numbers are not repeated in minorLabels

* Putting the examples into a loop

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Add .travis.yml file

* Add experiment travis code

* Fix react example

* Add pausing of rangechanged in scroll

Add subgroup updates to Item.setData.
Remove group updating logic from ItemSet._updateItem.
Fixes #2939