Added manual resyncing of subtitles

Added currently synced version to the sync history page.

Added view in the externalsites app to resync subtitles for a given
video url.

Added a method models.get_account_for_videourl()  Made
lookup_accounts() use this method.  lookup_accounts() now assumes 1
account per team, which is fine since it's a one-to-one relation.

Updated logging config for the docker dev environment.  It now prints
any INFO and higher log.  Also the format is a little nicer.