MILESTONES:
- read CD TOC including pre-gap information
- detect read offset
  (using a CD in AccurateRip and ripping with various offsets)
  (can be delayed since we can get the number from EAC)
- rip a CD with HTOA and other pre-gap tracks, creating separate track for HTOA
- parse .toc files (see cdrdao)

TODO:
- check pregaps more than once, to see if results are consistent, or with
  different methods
- handle errors on cdrdao spawning (for example, not having cdrecorder,
  or not putting the disk in)
- check if it's simple to listen to each track in a multitrack completing
- save trms to a pickle, after finishing each track
- figure out if cdrdao detects the pregap with one frame missing, or if EAC
  detects pregap with one frame too many
- add a way to store configuration data per drive, like offset
- rip the data session
- add AccurateRip validation for ripped images to rip command
- add GUI
- persist RipResult so rips can be aborted and continued too; needs verification
  of previously ripped files
- write moovida plugin
- cache results of MusicBrainz lookups
- on ana, Goldfrapp tells me I have offset 0!