store comment topic in a separate table.
cleanup pending comment & commentable.
fix get_comments.
fix view_for_question bug.
add some notes to the comment controller on things to do.
update leaderboard ranking.
Merge branch 'development' of github.com:Coursemology/coursemology.org into development

* 'development' of github.com:Coursemology/coursemology.org:
  remove compiled assets from dev
  tutor leaderboard
Merge branch 'comment_refactor' into development

* comment_refactor:
  add some notes to the comment controller on things to do.
  fix view_for_question bug.
  fix get_comments.
  cleanup pending comment & commentable.
  store comment topic in a separate table.

Conflicts:
	db/schema.rb