make cmake variable naming unique so that external cmake options are not overwritten
make cmake variable naming unique so that external cmake options are not overwritten

sarbian/libsquish,Zaretto/libsquish,wnoise/libsquish,nbtdev/libsquish,sarbian/libsquish,Zaretto/libsquish,sarbian/libsquish,nbtdev/libsquish,wnoise/libsquish,AmbBAI/libsquish,AmbBAI/libsquish,nbtdev/libsquish,AmbBAI/libsquish,wnoise/libsquish,Zaretto/libsquish