@manager update, db_uri and muic_dir environment variables
Album addition and Track altered also
shorten names, more concise
backref'd album in Track, manage updated

I've left notes in-line about problems which I'll list here
- creates a new album entry in the db for each track in the album
- search is not functioning (not sure why this is)

the Album entries seem to work as expected and we can add the date,
label and such later.
forgot one