* Timeline:
* Add overrideItems sub-property to timeline.editable
* Change behavior to override item.editable when overrideItems=true
* Added new example for timeline/editing to higlight differeing editable behaviors.
* Update timeline doc to reflect addition of timeline.editable.overrideItems
* Timeline - fixed logic oversights found in editable override testing
* Timeline - enable changeGroup when item.editable = true and not overriden
* Timeline - Small format changes to documentation and example pages for overrideItems
Alexander Wunschik
Simon Morris