Improve metadata matching based on thetvdb.com and themoviedb.org ID's

[DenyAll]

An extension of #839. Allow improved metadata matching for tv series and movies by allowing the series ID or movie ID to be included in the file name or folder - eg:

• using the thetvdb.com show ID, eg: My TV Show S01E04 [id77526].mp4 - would match Star Trek - The Original Series (thetvdb.com Show ID: 77526).
• using the themoviedb.org ID, eg: My Movie [id127585].mp4 - would match X-Men: Days of Future Past (themoviedb.org Movie ID: 127585).

I have suggested the use of idxxxx (where x is a digit) as keyword to match on, but whatever suits.