[fluid-dev] ENABLE_MIXER_THREADS not exposed at configure time

[Carlo Bramini]

Hello,

actually, the ENABLE_MIXER_THREADS allows to make FluidSynth working in 
single-thread mode if it is undefined. In this way, porting requires much 
simpler implementation, by leaving many functions as empty stubs. But at the 
moment it is not possible to modify it dinamically, since it is forced into 
fluid_rvoice_mixer.c.

Perhaps, it would be worth to make this feature available at configure time 
when launching cmake.

Sincerely.