Merge pull request #228 from dirkcuys/master

Small bugfixes for user permissions and notification preferences
Merge pull request #230 from dirkcuys/master

Fix incorrect exception catched
Merge pull request #232 from dirkcuys/master

Disqus SSO and default "find great coures" to community picks
Merge pull request #233 from dirkcuys/master

School home page HTML and disqus SSO updates
Merge branch 'master' of github.com:p2pu/lernanta
Add user URL to disqus SSO data
Add code for disqus SSO to content discussion
Include avatars for disqus SSO
Default to community picks for front page and remove staff picks from "Find great courses" page