Fixed a bunch of issues with the follow buttons

Correctly render Following/Not following on the language page.  Fixed
follow all languages/unfollow all languages on the backend side.
Switch the label to say "Following" when the user clicks follow all
languages.
Switch to the dummy backend on docker dev

This makes emails not fail, which was causing
send_video_comment_notification to also fail.
Link to correct page for comments on languages (#700)
Include language name in comment messages
Merge pull request #1132 from pculture/gh-700

Gh 700