Fixes to onDocumentDrop

* Rename relocating to relocatingNode
* Remove setTimeout, we preventDefault the drop event
  so we don't gain any information by waiting for the event
  to happen.
* Prefix the JSON string in IE mode to avoid trying to process
  real text drops.

Change-Id: I0bd39b958944b6b3e308c51dcb37292694c710a8
Merge "Fixes to onDocumentDrop"