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