Merge pull request #285 from AvadootNachankar/mongokit

Implemented - get_possible_attributes() function and history creation/updation for GTriple documents
add relation in custom app
Merge branch 'mongokit' of github.com:gnowledge/gstudio into mongokit
modified method walk in ajax_views.py file
modify in custom app
Added rectangles and Ellipse to graph nodes. Code modified to view saved nodegraph.svg in image-viewer.
Merge pull request #286 from Dhiru/mongokit

inclusion of relation in custom app
Merge pull request #287 from kedar2a/mongokit

Added rectangles and Ellipse to graph nodes. Code modified to view saved nodegraph.svg in image-viewer.
changed ajax messege in Make module
Merge branch 'mongokit' of https://github.com/gnowledge/gstudio into mongokit
Addition of GAttribute and GRelation inadmin data module
add default fiedls tags and content
Merge pull request #288 from Dhiru/mongokit

Addition of default fields in custom apps
updated attribute_type script
Merge pull request #289 from krishna31/mongokit

aatribute_type script updated
corection done in update_attribute_type_modified.py
Merge pull request #290 from krishna31/mongokit

corection done in update_attribute_type_modified.py
bug resolved in Make Module occured due to changes in models
Merge pull request #291 from krishna31/mongokit

bug resolved in Make Module occured due to changes in models
Creating history (version-file) for existing GAttribute documents