* The next fix on Travis unit test failure

This is the next escalation on the war against the Travis unit tests failing (which came into being by yours truly).
By accident, I could recreate the unit test failure on my development machine. This led to a more directed effort to
squash the bug.

The insight here is that test `(window === undefined)` fails, but `(typeof window === 'undefined`)` succeeds. This undoubtedly has to do with the special status `window` has as a global object.

Changes:

- Added check on presence of `window` in `Canvas._requestNextFrame()`, fixed local source errors.
- Added catch clause in `CanvasRendered._determinePixelRatio()`
- small fix: raised timeout for the network `worldCup2014` unit test

* Preliminary refactoring in utils.js

* Added unit tests for extend routines, commenting and small fixes

* More unit tests for extend routines

* - Completed unit tests for extend routines in
- Small fixes and cleanup in `util.js`
- Removed `util.protoExtend()`, not used anywhere

* Added unit tests for known font options

* Corrects usage of @static jsdoc annotation

* Correct unresolvable types

* Correct types in jsdoc and remove extraneous @class & @constructor jsdoc

* Remove incorrect @static jsdoc

* Adds missing jsdoc for param copyFromGlobals

* correct jsdoc in util

* Corrects casing on jsdocs

* Swaps @inheritDoc to @ignore for constructors where constructor args are documented in the class

* Instantiates Errors with `new`

* Addresses improperly defined @callback tags.

* Split callbacks out to separate jsdoc

* Moves constructor jsdocs back to constructor and drop @ignore.

* Added commenting for options, refactored choosify()

* Refactored updateLabelModule()

* added comment at node creation

* Completed fix for #3350

* parseOptions() different handling for bridged/extended; unit tests for reversal of options

* Fixes on linting and unit testing

* Enables require MethodDefinition for require-jsdoc lint rule and corrects 66% of missing Method Definitions

* Adds jsdoc for all remaining methods and corrects @class/@constructor documentation

* Define values more accurately

* Correct bugs that prevent jsdoc generation

* Removes redundant .eslintrc from graph3d, lints the rest of the code base, and enables valid-jsdoc lint rule

* Corrects lint violations

* Change lint rules

* Get eslint passing with require-jsdoc

* Fix mergeOptions() and add unit tests

* Removed comment

**Note: ** This is a simple fix and should be easy to review.

Fix for #2579

- Adjusted node title definition in `options.js` to allow DOM elements
- Changed `BridgeObject()` in `util.js` so that DOM elements are *not* bridged.

Fix for #2856

- Toolbar gets reshown when cancelling edit node dialog
- No shadow displayed upon save in edit node dialog

The latter is actually a more general problem. Function `mergeOptions` in `util.js`
made an assumption as to the correct value of field `enabled`. It now takes the value
from `globalOptions`, if present.

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

* Adjust to better process class names

* 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 selectiveExtend accept null/undefined parameters

* 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

Fixes: #2490 (on the correct branch this time)

* element characteristic changes
* assume edge color inheritance is correct before choosing
* Adjust nodes’ chosen’s boolean -> bool
* Need to get user-reset size
* make example edges thicker for more noticeable shadow
* preemptive ES6 fix (see #2500/#2501)
* documentation for the feature that was previously overwritten

Fixes: https://github.com/almende/vis/issues/2490

* Fix redraw order
* Add elements censor and event to emitter
* Fix all recursive loop in json event
* Add docs for event emitted

* Multifont node and edge labels
* adjust documentation
* rework mod-font property inheritance
* Node max/min widths, min heights; Edge max widths
* Accumulate sizes correctly for unconstrained multipoint labels
* handle font.multi when groupOptions.font is not declared
* propagate label fonts on changes, not just creation
* Allow top-level constraint numbers
* accumulate width and empty lines appropriately

* Add initial scroller without options
* Add initial scroll without an option
* Add verticalScroll option
* Fix scrollbar positions
* Add docs
* fix example
* remove jquery dependency
* Fix example
* Fix review comments

- Fixed #1528, #1278, avoided ID's being cast to string for methods that return ID's as well as storePositions casting to string.

Provide the DataView.map() method similar to the DataSet one.

Added the following:
- dashes property to nodes in options.js
- dashes property with value false to defaultOptions in NodesHandler.js
- support for Arrays to selectiveNotDeepExtend function in util.js
- functionality to CircleImageBase.js that allows circularImage nodes to have dashed borders
- example demonstrating how to apply the dashed border to a circularImage node
- documentation explaining the usage of the dashes property on a node

- Dropped support for appending data returned by `DataSet.get()` to an existing Array or DataTable.
- Fixed a `window` issue in uuid.js.