Add a sentence about Mac OS X in devdoc
Add a sentence about Mac OS X in devdoc

nezticle/fluidsynth,nezticle/fluidsynth,FluidSynth/fluidsynth,FluidSynth/fluidsynth,FluidSynth/fluidsynth,nezticle/fluidsynth,nezticle/fluidsynth,FluidSynth/fluidsynth