Added context menu option for reindexing
Removed click canceling block that was preventing move operations to items in the same folder.  Move now only triggered if dropping on the title of the target folder.  Broke out MoveDropLocations into its own class
Added onChangeEvent to structure view so that it can inform the UI when its contents change.  Using this to resolve problem of the search menu becoming larger than the allowed space after expanding a folder or loading the parent container