lots of improvements

- logging now goes to a file, and not to stdout. cleaned up old logging
files and stuff
- fixed doubles of songs showing up
- dicts have been extended to allow multiple vals, which gives us
ability to look at multiple outcomes for a single seed
- updated the harmonic mixing dict to correct matches, which also fixes
the 0 & 1 cases (they weren't included before by accident)
- for 0 & 1, filtered out the cases where errors come back from API call
(see above - this is the case where you have a 1 where the keysig cant
be deciphered vs. a 01 which is an acceptable value)
- put in restrictions for # of songs in a mix to restrict capsule.py's
failures to handle really long mixes
- changed to 30 sec per song in mix, fewer iterations
- other minor code cleanup and refactor