* fix #2613 with if statement, and null for pointer value rather than referencing it when undefined

* removed if statement, since not needed, and updated documentation to note the null pointer property in certain conditions.

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

* updated HISTORY.md for v4.18.0
* bumped package version to 4.18.0

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Add .travis.yml file
* Add experiment travis code
* Fix right click button bug when dragging item

* fix(graph2d): fix #2500 for graph2d; improves #2580

* fix(DataSet): make sure the right id-type is used internaly

This fixes a fixed strange string-number conversion issue.
It can happen that id "0" !== 0 what causes #2580.

fixes #2580

* address IE11 issue 'Symbol' is undefined with babel-polyfill  

https://github.com/almende/vis/issues/2560

* address IE11 issue 'Symbol' is undefined with babel-polyfill

https://github.com/almende/vis/issues/2560

* address IE11 issue 'Symbol' is undefined with babel-polyfill

https://github.com/almende/vis/issues/2560

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Fix #2538

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

- Also updated docs and examples for this
 - Fixed the positioning of the tooltip if groups was enabled
 - Removed missing parameters from Popup docstring

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Fix boolean types bug

* Add subgroup stacking

* Almost finish subgroup stacking

* Play with examples for subgroup order

* Fix stacked subgroups

* Fix subgroup stacking

* Add stackSubgroups option

* Fix example

* Add docs

* Fix onRemove item subgroups recalculate

* Return subgroup example and add stackSubgroup example

* Split stackSubgroup example to subgroup/html and expectedVsActualTimesItems.html

* Fix small bug when subgroups start overlap

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

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Fix react example

* Fix redraw order
* Add mouseup, mousedown, mouseover, click and dblclick events on timeline
* Add docs
* Add to evenlistener example
* Add mousemove event listener
* Fix example
* Remove mouseUp and mouseDown events and fix docs for mouseOver
* Remove mouseUp and mouseDown from example

* Fix redraw order
* Fix error when option is not defined
* Allow template labels
* Fix boolean types bug
* Add subgroup stacking
* Almost finish subgroup stacking
* Play with examples for subgroup order
* Fix stacked subgroups
* Fix subgroup stacking
* Add stackSubgroups option
* Fix example
* Add docs
* Fix onRemove item subgroups recalculate
* Return subgroup example and add stackSubgroup example
* Split stackSubgroup example to subgroup/html and expectedVsActualTimesItems.html

* generate custom builds into the dist folder

* updated the we-need-help link in the readme

* general improvements of the readme

* Allow pass the color of points in 'dot-color' mode of Graph3D explicitly - clear the source code and finalize
* Add an onclick callback in Graph3D, to enable click and display customer user-defined information for single data point
* Extra data type validation for string conversion functions in Setings
* Disable onclick callback immediately after rotate/pan
* Re-format the JavaScript file
* No onclick event set by user - properly treat this case now
* Further reformat - indentation
* Handle the case where there is no closest data point

* Added HTML tooltip support for Timeline

* Fixed tooltip position on Firefox

* Added Timeline tooltip example

* Updated tooltip location to be next to the mouse

* Added HTML element to example

* readded depricated option throttleRedraw; fixes #2511

* added doc style for depricated options

* move all babel options to .babelrc file

* updated babel-loader

* 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

* Fix groupEditable
* Fix group drag in vertical direction bug
* Fix indentation
* Add initial nestedGroups property
* Fix redraw order
* Get nested groups hiding working
* Add order to nestedGroups
* Fix up example
* Add support for intially closed nested groups
* Add nested groups indentation
* Fix indents
* Add nested groups docs
* Fix example
* Revert indents
* Add classes to nested and nesting group labels and add nesting group css
* Use pure css for nested group icons
* Remove commented off lines and unnecessary btn
* Fix indents
* Add support to showNested:false in group
* Add semicolon
* Remove empty lines

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Fix boolean types bug

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

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

* Fix redraw order

* Fix error when option is not defined