Remove dry_move() method.

dry_move() was rather useless as it only printed some information to the
screen and didn't actually do any of the work that move() did, now
move() simply checks if the dry flag is set to false before copying
files over.

Files support check is left up to taglib now, by opening the file using
taglib and check if that raises an OSError, if it does that means its
not supported.
Update TODO
Update README