Merge branch 'rc' into release

* rc:
  pick up new ora2 (7/21 -> 8/08)
  make unit tests respect mongo port/host settings (with default)
  Fix json_update_videos()       commit (1f5c95b) to transcript_utils.py changed the sig of download_youtube_subs     from def download_youtube_subs(youtube_subs, item, settings):     to def download_youtube_subs(youtube_id, video_descriptor, settings):
Merge branch 'release'

* release:
  pick up new ora2 (7/21 -> 8/08)
make help center link a visible button
Merge pull request #108 from Stanford-Online/giulio/help-modal-tweaks

make help center link a visible button