FluidSynths overflow priority calculation, that determines which voice to
kill if the current polyphony limit has been reached, treats all channels
as equal. Only percussion channels can get a user defined score added to
their priority.
In certain use-cases there can be a number of MIDI channels that are much
more important than other ones, and not just percussion channels. For
example, a channel playing a constant pad sound which would be very
noticeable if killed.
This change adds two new synth.overflow settings:
- synth.overflow.important
- synth.overflow.important-channels
They add the ability to mark MIDI channels as "important" and have
the overflow calculation add a user defined score to voices on those
channels.
