don't redefine if defined already
Support for multiple sound buffers/voices

    * In preparation for adding mockingboard support
    * NOTE: ALSA still has a hardcoded 1 buffer assumption with its use of mmapped access
include uthash.h
First cut at supporting mockingboard.

    * Now using OpenAL as the main backend, ALSA has been deprecated...

    * soundcore-openal.[hc] - OpenAL sound output for emulator

    * alhelpers.[hc] - OpenAL suport files

    * mockingboard.[hc] , AY8910.[hc] , SSI263Phonemes.h - Mockingboard support ported from AppleWin ...
Merge branch 'mockingboard'

Conflicts:
	src/cpu.S
	src/misc.c