Added basic comment UI. closes #75

- Adds new comments automatically
- Adds new comments on Faye events
- Doesn't limit by number
- Only gets collection when view is toggled open, then continues
  to listen for comments on that thread. Doesn't fetch again.
fixing tests
adding comments_collection test. #75
put newest comments at the bottom
Merge pull request #76 from cremalab/comments-ui-75-rb

Added basic comment UI. closes #75