TODO items:

Scheduled for 0.6.4:
--------------------
- Config subsystem with in-game config changes
- safer VM support for strings

Not scheduled:
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Architectural:
- gfx subsystem remodelling for proper palette emulation support
- gfx widget subsystem remodelling to reduce fanciness and increase
  similarity to classic SCI rendering
- MT-32 -> GM mapping (investigate direct timidity support)
- The sound subsystem doesn't use proper locking, which might
  introduce race conditions -> introduce abstract locking API
Testing:
- test song iterator repetition, fix where neccessary (this one's not
  neccessarily so long-term)
Other:
- Adjust MT-32 midiout to assume a max rate of 3125 bytes per second.
  Ensure that we wait long enough after each sysex.
- Fix realtime song player detection of situations in which too much
  time has passed
- if scaled images are turned off, drawing SCI1 (pixmap) backgrounds
  is completely broken for scaled (-x2 etc.) sizes. Fix this!
- Status bar: When removed, recover background (as opposed to just
  drawing black)-- fixes Jones16 menu bar

