Bank select mode in response to system reset.

[nanitaro]

Hello.

Current fluidsynth seems to correctly accept only GM system on.
See also #1323

It would be useful to be able to initialize according to the type of system reset and automatically switch bank select mode as well.

For example, setting synth.midi-bank-select to "auto",
The bank-select mode is switched according to the received system reset.
GM system on -> synth.midi-bank-select = gm behavior
GS reset -> synth.midi-bank-select = gs behavior
XG System on -> synth.midi-bank-select = xg behavior

GM2 seems to need a new bank select mode.
-Select bank by LSB(CC32).
-MSB(CC0) is 120(78H) for drums, 121(79H) for melody.
See also General MIDI 2 3.3 Control Change Messages http://www.shclemen.com/download/GM2.pdf

The point is to emulate the device according to the reset type after resetting.
I think it would solve problems like #228.
As for the badly behaved SMF files that have not been properly initialized, I don't think there is any problem with the existing specification.
(Manually select bank select mode if necessary.)