The objects for handling markup data in Video objects are created when
the video entry is pushed to the database. The metadata import routines
require a database entry to operate against, while the filename
generator requires the import routine to be run before a filename can be
specified. This in turn requires a dummy entry be created with a blank
filename, which results in a broken markup handler.
This fix manually corrects the markup handler object after a filename
has been chosen, to map it to the correct video.
Fix from CiaranG
Adds two options (--safe and --really-safe) to be used to confirm a
correct export of the source material. --safe just checks resultant
filesize, while --really-safe performance a (lengthy) SHA1 comparison of
source and destination. The --delete option enforces the use of at least
--safe.