Fn hierarchy; Migrating, Remove, and Add work

Migrate now migrates starred status to Spotify version of track.
Added ability to archive at artist and album level
- archive.artist.current
- archive.artist.fromURI
- archive.album.current
- archive.album.fromURI
Remove artist/album now expanded to support local files; Searches out
artist and uses server to retrieve tracks to remove.
- remove.artist.current
- remove.artist.fromSpURI
- remove.artist.fromLocal (will likely consolidate these two into a
single .fromURI)
- remove.album.current
- remove.album.fromSpURI
- remove.album.fromLocal (will likely consolidate these two into a
single .fromURI)

...will continue plumbing Add, Remove, Archive, and Migrate...