Implemented function that returns possible relations (inverse-relations as well) of a given node (or list of nodes).
Merge pull request #272 from AvadootNachankar/mongokit

Implemented function - returns possible relations (inverse-relations as well) of a given node (or list of nodes).
Merge branch 'mongokit' of https://github.com/gnowledge/gstudio into mongokit
modified page.py according to the change in class GRelation