Rename retry

Sometimes the file would report as being in use when trying to rename
the file in preparation for qtfaststart to do its thing, This allows the
script to fail and retry 3 times with a 10 second delay in between.
Should make things more reliable.
Nonetype safety improvement

Better version that removes Nonetypes when they are found (shows with
little metadata) before attempting to save the file, which will cause an
exception.