Merge pull request #329 from sunnychaudhari/mongokit

Bug resolved. Breadcrumbs for collection navigation implemented successfully
Only last_update field gets reset whenever SystemTypes are edited.
Merge pull request #330 from AvadootNachankar/mongokit

Bug resolved: created_at field getting reset whenever SystemTypes are edited (via admin-interface)
Commented few lines regarding loaction field.
user_access_policy() modified: group_set field is replaced with author_set field.
Merge pull request #331 from AvadootNachankar/mongokit

Bug resolved: Visibility issue of Edit button
Bug resolved for group collection display