[musicdb] rewrite the info scanner, music database and gui windows for musicbrainz
[musicbrainz] Update the Scanner & Scrapers to support ID resolution for MusicBrainzIDs
[musicdb] refactor out FindAlbumInfo and tidy up some common code
[musicdb] add join phrase to musicbrainz to support album artist resolution from musicbrainz
[musicdb] implement a per host rate-limiter to avoid hitting the musicbrainz rate-limit and be more friendly to our peers. also update the MB scrapers so they cache properly (caching by filename) to remove www. and make http://musicbrainz.org the standard.
[musicdb] fix: add compilations, song artists and song musicbrainzIDs to the XML
[musicdb] support reading/writing compilation flag from the scrapers
[musicdb] support reading/writing song credits from the scrapers