* customTime read-only (i.e. editable = false) patch.

* updated docs for read-only customTime patch

* add global 'groupLabelDirection' option

* update docs

* initial trial

* Add onInitialDrawComplete

* Add docs

* Add to eventListeners examples

* Keeping things DRY

* Remove callback insertion

* Remove call

* Add initial loading screen

* Fix real initial draw call

* Remove activateOnInitialDraw method

* Add loading screen option

* Add docs

* Remove onInitialDrawComplete double doc

* Simplify example

* Simplify stressPerformance example

* Remove extra line

* 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

* 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

* Add initial itemVisibleFrame

* Add visibleFrameTemplate option

* Improve example

* Rename and fix example

* Fix comments from PR

* Fix example

* Add initial support for rolling mode
* Add rollingModeBtn and simplify example
* Make icon in css:
* Remove icon btn
* Add docs
* Fix zoom in rolling mode and initial start/end times

* Fix mouse zoom on currentTime
* Fix customTime mousewheel bug

* Add initial onChange item tooltip
* Add example and tooltipOnItemEdit template option
* Add docs and rename option
* Fix docs
* Fix example
* Change example's item types
* Fix point item tooltip
* Fix comments from PR and support bottom orientation properly
* Add semi-colon

* Hide vertically hidden ranged items in groups that are not visible
* Add element to templates options
* Fix comment typo
* Add documentation for react mounting
* add react example
* Fix typo
* fix title
* Fix review comments
* Add vis-drag-center to fix dragging bug when template is react component

* 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

Timeline will check for the property 'editable' on individual items.

  if editable === true
    ignore timeline option 'editable'
    allow item to be edited
  else if editable === false
    ignore timeline option 'editable'
    do not allow item to be edited
  else
    use timeline option 'editable'

If two items are selected and one is not editable, only the editable
item is draggable.

This change required the css class .vis-editable be moved from the
item set to the individual item containers to maintain proper styling.

This is primarily designed for the graph2d line graph.