* Add initial experiment
* Register drag and drop events
* Add initial drag and drop support
* Add drag and drop support for all types of objects
* Fix example
* Clean up code and add comments
* Fix example
* remove font awesome
* Fix example style
* Add meta tag to example and add selected when dropped

* 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

Add flag to check whether an item in the Itemset is currently being dragged

added docs

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.