The main instrument groupings were already pretty good but there
was some room for improvement. The generated configuration sounds
pretty good now, even when using the 256KB config.
Regroup GUS percussion instruments based on personally having listened
to the samples in the GUS instrument set and identifying similar-
sounding instruments.
Replace the current poor-quality handcrafted GUS configuration with
a script that programatically generates an optimized configuration
file based on statistical analysis of music from various popular WAD
files.