Allow splitting Mythmusic metadata fields into >1 value

[herman@…]

Attached patch adds a setting to mythmusic, with which one can set a value separator for the various metadata fields. It is more or less a quick fix for a minor issue: I've got a few CDs which I would like to put into 2 genres, and duplicating the records in the metadata doesn't seem to be a nice solution.

When the setting "FieldSeparator?" is set to a string, records in metadata which contain that string are put in each of the values separated by the string. For example, rows with a genre value of "Classical|Soundtrack" and a "|" separator, will appear in both "Classical" and "Soundtrack". It should also work for the other metadata fields.

Haven't bothered adding a GUI setting, as I'm not sure if it will be used often enough to warrant one.

[herman@…]

Patch against r6792

[Isaac Richards]

I think this would better be handled at the database level, instead of hacking it in like this. Ie., have a 'genre' table, with each metadata entry able to refer back to it.