HTML5 Video errors + WEB_NO_TONO flag + thumbnails

- Added fallback large/medium thumbnails
- Errormessage for web added
- settings.py: new WEB_NO_TONO boolean stops videos
  with TONO-flag from being published:
HTML5 Player errors + WEB_NO_TONO

- settings.py: New WEB_NO_TONO stops videos with the TONO-flag
  from being shown
- Added a way to show errors with the player
- Added large/medium thumbnail
Error explanation + Better error messages
And resize the thumbnail
Merge pull request #22 from Frikanalen/vod-errors

HTML5 Player errors + WEB_NO_TONO
Fix obvious missing line. + Cleanup.

Removed some commented out code that doesn't work anymore anyway