Ignore/mark-as-viewed buttons work
Back-button from channel-view, better spinner, no nonfunctional search bar in title
Tidyup mark_viewed/mark_ignored methods
grab_video task acks_late
Loading thing for channel-view
Unused
Missed bits of loading indicator
Fix relative timestamps

timeago doesn't magically work with dynamically-modified DOM, so use
angular-moment instead
Routinely update statuses
Cancel periodic refresh when navigating else where