Removed unused LMS templates. Renamed LMS templates to have same name as discussion XBlock templates
Merged LMS templates to discussion XBlock
Merged views + removed js files
Removed generated js scripts and added them to gitignore
Fixed errors in discussion XModule, caused by c2716d470c97bfd01658b815d2f3725628b186fa:
1. Enabled `thread_type` selector for inline discussions
2. Fixed missing `commentable_id` (Javascript null was encoded as string 'null', not null object)