Merge pull request #779 from kedar2a/mongokit

img/ added to gitignore and little modifications in data-review
Specify django version in requirements.txt (issue #778)
Merge pull request #780 from m-anish/patch-1

Specify django version in requirements.txt (issue #778)
shelf code added
alerts placed for shelf_item add and shelf_item removed
Links of images in Iframe (html resource) disabled
Merge pull request #781 from kedar2a/mongokit

Links of images in Iframe (html resource) disabled
Page/File delete error solved
Merge pull request #782 from anujag/mongokit

Page/File delete error solved
Merge branch 'mongokit' of https://github.com/gnowledge/gstudio into collection
Shelf block added
'shelf_allowed' tag added to allow the shelf items to be added in user shelf
template for displaying shelves and shelf items
code added for allowing node to add as a shelf item in user shelf
code added for deleting shelves and shelf items
Merge pull request #783 from sunnychaudhari/collection

Shelf is activated now
Code added for displaying user shelf for page, file,browse topic, browse resource
Merge pull request #784 from sunnychaudhari/collection

Code added for displaying user shelf in varoius apps
Merge branch 'mongokit' of http://github.com/gnowledge/gstudio into mongokit-explore-resources
Pagination implemented in data-review