Implement the Relationship model
Add a 'followed streams' page
Add follow/unfollow buttons
Improve the 'followed streams' window
Follow/unfollow buttons now use Ajax
Follow/unfollow buttons now use Ajax
Merge branch 'sp7.sc3.subscribe-to-streams' of github.com:projectcs13/sensor-cloud-website into sp7.sc3.subscribe-to-streams
Fix conflicts