* Added ASCII media processing
* Added ASCII media display
* Added ASCII media type
Rebased from Joar Wandborg's ascii art branch (squashed to remove the
commits borrowing code of dubious license)
Fixed a bug in file submission error handling:
- Moved file-extension condition out of loop (what did it do there?)
- Updated file submission tests
- Changed error handling in file submission, should now report more
than absolutely necessary.
