[DRAFT] OGG support
MOAR CONVERSION DRAFT
Removed unused properties
Better docstrings
/convert without mimetype converts all
Replaced JSONResponse(404) with abort(404)

When a 404 was encountered, the JSONResponse object was trying to be
marshalled. The abort function, on the other hand, raises an Exception,
aborting the execution of the script.
FIXME
Introduced MimeType object
Convertion docs