Setup active RGSS version at runtime. Desired version can be
specified via config, or as default, auto detected from the game
files. This removes the need to build specifically for each
version, which should help packaging a lot.
This also greatly reduces the danger of introducing code that
wouldn't compile on all RGSS version paths (as certain code paths
were completely ifdef'd out).
This can be optimized more, eg. not compiling shaders that aren't
needed in the active version.
This adds a new dependency with libfuildsynth. MIDI support
is built by default, but can be disabled if not desired.
All RTP songs should work well, but there are known problems
with other files (see README). Also, the pitch shift implementation
is somewhat poor and doesn't match RMXP (at least subjectively).
A soundfont is not included and must be provided by
the user themself.
Jonas Kulla