Merge pull request #260 from AvadootNachankar/mongokit

Implemented thumbnails and edit option for Media files (partially)
Bug resolved in ajax call for collection widget
Merge pull request #261 from sunnychaudhari/mongokit

Bug resolved in ajax call for collection widget
Graph Bug resolved
Merge pull request #262 from kedar2a/mongokit

Graph Bug resolved.
Url modified to accept node's id as second parameter (previously accepting 'home' as a value)
Mongodb query synatx modified and HttpResponseRedirect() modified.