'attribute_set' & 'relation_set' fields added under GSystem class.
Script updated to add 'attribute_set' & 'relation_set' fields with default values (as []) in all existing GSystem documents.
Merge branch 'mongokit' of https://github.com/gnowledge/gstudio into mongokit
Merge pull request #805 from AvadootNachankar/mongokit

Changes in models.py (GSystem class)