[enh] slight enh to the navbar : justify the items
[fix] better join/leave course button
[enh] send notif only if it is an insert not an update
Merge branch 'master' of git://github.com/titouanc/beta402
[add] add signals to processing deamon
[fix] rule renaming: run -> start
[fix] join/leave is now handled by users app, 
allowing for all types of nodes to be followed with /zoidberg/users/join/<nodeid>
and unfollowed with /zoidberg/users/leave/<nodeid>
Fix merge conflicts