Bug fixes. Reinforced leave animation

- Last video in the list will move slower than the others in previous
  version
- Leave animation should now consitently play
- Removed unnecessary masonry.reloadItems calls, extra elements don't seem
  to come up, and animations are already robust without them. They also
  throw error sometimes.
- Removed !important for masonryTile, not necessary.
- When hub page is open and new videos are detected, switching to all
  videos and displaying all videos should now work more consistently
Remove channel update. Fixed animation desync issue.

- Removing channel now properly removes the videos corresponding to that
  channel
- A little bit of refactoring
Merge branch 'master' into activities_checking