Issues:

* only handles waveforms less than 64k frames (unfortunately this seems to
  be a hardware restriction so not much can be done about it)
  NOTE: the 64k limit is NOT in bytes, but sample-frames! this means that
  it's possible to play 128kb 16-bit samples, 64kb 8-bit samples and 32k 4-bit
  ADPCM samples. also note that ping-pong loop causes part of the loop-portion
  to be copied and this will eat sample-frames so try to minimize the use of
  ping-pong loops.

* arpeggio command is not fully implemented

* tremor command is not implemented

* set finetune command currently has no effect.  

* glissando slides are not implemented

* delay note seems bugged (just noticed, maybe affects other similar cmds)

* amiga frequency table is currently not (correctly) implemented

* SH4 loader is incomplete so module must be pre-converted using the
  host converter...

* loader only handles the XM-format, though MOD, S3M, etc can be added
  with "relatively" ease (or that was the intention anyway...)

* Maybe make control.o into a library instead? (nah, not really worth it)

* ARM was too slow so i moved one-shot waveform playing to the SH4 side instead
  but this is completely untested....


Known bugs:

* sound is noisy, probably due to bug in interpolation code in envelope
  processing (will look into that momentarily)

* Still something wrong with BPM...module plays slightly out-of-sync,
  this is maybe due to inaccuracy of the timer-irq..check the calculations

* volume conversion from linear to logarithmic is incorrect

* Figure out how to get ld to align the .o files properly. changing
  the order of the module and player causes misaligned data with
  a address-error as result (when trying to write to sound-ram). this
  is annoying...

* slow code. playing 32 channels is not working with full envelope
  processing (maybe works at a lower BPM than 125 but still).
  pan envelope can be turned off if necessary to speed things up
  a bit...

* Some (most?) modules just play incorrectly. I dont really know whats going
  on...even if aica only handles 64k waveform doesnt mean that there should
  be noise which is the most common symptom...others include playing of pattern
  screwing up, erranously repeating part of the pattern etc...
  hmm...could it be bugs in the converter? oh,well....
