Bug fix for Group dashboard and other improvements

**Check implemented for editing feature on group dashboard**
1) templates/ndf/group_dashboard.html
  - Only logged-in users can have access to edit feature

**Other improvements**
1) views/course.py
  - Fetch colleges which are registered under MIS_admin group

2) views/home.py
  - 'home' group's url modified to redirect to group's new dashboard url.

3) views/userDashboard.py
  -  Fetch has_profile_pic and has_Banner_pic, only if both have values respectively in their corresponding node's relation set.