Feature/arjun/fix discussion sync

Retrieving video information from YouTube using https instead of http.

Make heartbeat url wait for courses to be loaded

adding maintenance static data

Limiting depth of comments

Feature/forum config

cs188 styling

Get rid of inline flag for choicegroup, radiogroup, and checkboxgroup. 

Fix error when unicode string is in message viewed in single-thread

added a loading icon when retrieving ajax

add user profile and fixed edit

Add subdomain_branding key to aws settings

Get rid of inline flag for choicegroup, radiogroup, and checkboxgroup. This should be done via CSS. This change only affects radiogroup and checkboxgroup as far as changing the behavior goes