Enmet

Fix for search_bands failing when countries parameter is used.

- Added random_band(). Used mainly for testing, but may be useful for some random exploration.
- Better handling of empty values, like "Unknown", "N/A", ["N/A"], "" etc. Now all such data is returned as None or [] (empty list).
- Change repr and str for EntityArtist subclasses to use names from specific entities, not from underlying Artist. This is to avoid fetching Artist page just to display name, repr or str.
- Minor fixes
- Split code into smaller modules

Fix search functions (in some cases search results could be empty, while on Metal Archives page the same searches would return values).

Band.past_members
Band.live_musicians
Band.info
Band.last_modified

Artist.age
Artist.place_of_birth
Artist.gender
Artist.biography
Artist.trivia

Band.similar_artists

SimilarBand

Initial release