added twitter block to class homepage, but it needs to be generalized...
changed to using 'course_prefix' as part of the twitter handle (eg. @ 'db' class) this should pretty much fix #2247
changing back to hardcoded twitter handle, will revisit later with input from @jinpa and others (#2247)
moved code into a django block and made it appear only on the homepage
Merge branch 'master' of https://github.com/Stanford-Online/class2go into giulio-twitter-widget-2247
final twitter widget code changes (using twitter widget version 2)
Merge branch 'master' of https://github.com/Stanford-Online/class2go into giulio-twitter-widget-2247
Merge pull request #2312 from Stanford-Online/giulio-twitter-widget-2247

Class Twitter widget on class homepage