Also - includes:
* Added 'parent_id' in the 'generate_browser_node' function of the Nodes
to allow them to move around the parents objects (specially through
update/save functionality).
* Handles the issue related to adding the older object back to the
collection (DataModel).
Author: Ashesh Vashi
Reviewed by: Neel Patel, and Akshay Joshi.
