Various updates

- Added itunes script to fix AlbumArtist tags (too many useless Various
Artists in BiRP.fm); just copying artist to album artist for selected
tracks
- various bug fixes related to making server portable, and separable
from spotify app (can be run on different machines)
- make dedupe() top level functions (calls dedupe.find() to start the
process)
- streamlined local to spotify migration, not moving anything unless
sptrack is found now, no need for separate iterations
-