Merge pull request #320 from supriyasawant/mongokit

separate tab created for pandora_video
MetaType added to collection_tuple; and try-catch blocks implemented in Node class's save() function.
Code added to save modified_by and contributors wherever missing.
Merge branch 'mongokit-dev' into mongokit
Merge pull request #321 from AvadootNachankar/mongokit

Bug resolved: Regarding modified_by field in models.py file (line #395)
Updated with code to add/modify modified_by and/or contributors field.
Bug resolved: Faulty values in modified_by and contributors for User-groups and Files
Merge pull request #322 from AvadootNachankar/mongokit

Bug resolved: Faulty values of modified_by and contributors fields in existing documents
under construction file wedget for custom app
Merge branch 'mongokit' of https://github.com/krishna31/gstudio into mongokit
Little modification in views
Merge pull request #323 from sunnychaudhari/mongokit

Little modification in views
Bug resolved in collection module(image & video)
Merge pull request #324 from sunnychaudhari/mongokit

Bug resolved in collection module(image & video)
bug resolved while adding instance to app via designer module
Merge branch 'mongokit' of https://github.com/gnowledge/gstudio into mongokit
Merge pull request #325 from krishna31/mongokit

bug resolved while adding instance to app via designer module
Now added makers position can be edited/change
Intermediate: Edit plus for editing TYPES.
Merge pull request #326 from kedar2a/mongokit

Now added makers position can be edit/change.