removed commented out ObjC WavObj code, enhanced error messaging
Renamed channels, numChannels to nChannels
Replaced manually defined PI with M_PI

http://stackoverflow.com/questions/1727881/how-to-use-the-pi-constant-in-c/1728959#1728959
Fixed for loop in performMix()

It was cutting out after finding the first inactive object, which would skip active objects past the first inactive one.
Implementing multi-threading for Mixer3D

Need to debug a compiler error "No matching function for pthread_create" due to a faulty argument. See also http://stackoverflow.com/questions/18057130/reference-to-non-static-member-function-must-be-called.