* Add methods to remove and add items to a subgroup.
Add method to change the subgroup an item is in.
No longer decrement subgroup ID when removing a subgroup.
Fixes #2594

* Moved the orderSubgroups call outside of the add/remove methods.
Added the ability to call the add/remove methods without a subgroupId parameter (takes from item data instead).

Don't update the showNested property if nothing has been set in the data object, unless it is undefined.
Verify group object exists during `onGroupClick`

Fix proposal for issue #2842

More details here : #2842

* Fix #2795 issue

* 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 options for zoomIn and zoomOut

* Fix background items when orientation top

* 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

* 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

This addresses #1982 and #1417.

It possibly reduces performance, but correctness seems better.

Clean up and centralise edit status for Timeline Items.

* 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

* 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

* 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

* 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

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

* 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 zoom below 1ms bug

* 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 mousewheel while dragging item bug
* Return removed lines

Fixes default end, and reduces duplicated code. Adds tests.

* 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

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Fix #2538

- 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

* 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

* 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

* 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

* Fix redraw order

* Fix error when option is not defined

* Fix redraw order

* Fix initial drag item bug

* Fix indents

* Fix redraw order

* Add initial itemVisibleFrame

* Add visibleFrameTemplate option

* Improve example

* Rename and fix example

* Fix comments from PR

* Fix example