Make "Enable vinyl track numbers" opt-in for new users

I keep seeing releases by new, confused users that look like this:

This    Is a Title
So      Is This

Rather than:

1    This Is a Title
2    So Is This

This seems to be due to "Enable vinyl track numbers" being on by default, which means any tracklist parsed that does not start with a track number will end up messed up. We should probably disable this by default.