Merge pull request #12 from Trott/refactor

split different "tables" into files
rm data.json
artist_track
Merge pull request #13 from Trott/artist_track

artist_track
add individual_artist relations
Merge pull request #14 from Trott/individual_artist

add individual_artist relations
individual_track
Merge pull request #15 from Trott/individual_track

individual_track
track_album
Merge pull request #16 from Trott/track_album

track_album
album->release
album -> release
allow multiple titles for a release
Merge pull request #17 from Trott/multiple-titles

allow multiple titles for a release
allow artists to go by more than one name
Merge pull request #18 from Trott/artist-names

allow artists to go by more than one name
allow individuals to have more than one name
Merge pull request #19 from Trott/individual-aliases

allow individuals to have more than one name
Merge branch 'master' into multiple-titles
allow multiple titles for a track