make credits page more useful

Garth Hudson was so talented and musically brilliant on a variety of instruments.  I'm revisiting his credits playing on other artists' sessions.  Since there's no advanced credits search (which would be a better idea than this one), below are some ideas to make the credits page more useful.

1. Allow filter to exclude composer as credited role.
2. Add filter for main albums and EPs.
3. Show editor ratings.
4. Show icon if editor reviewed album.