Added Game_Music_Emu, a decoder plugin for mpd.

Added is a library for playing video game music and an option to the mpd package to support it. From the Game_Music_Emu website:

Game_Music_Emu is a collection of video game music file emulators that support the following formats and systems:

AY 	ZX Spectrum/Amstrad CPC
GBS 	Nintendo Game Boy
GYM 	Sega Genesis/Mega Drive
HES 	NEC TurboGrafx-16/PC Engine
KSS 	MSX Home Computer/other Z80 systems (doesn't support FM sound)
NSF/NSFE 	Nintendo NES/Famicom (with VRC 6, Namco 106, and FME-7 sound)
SAP 	Atari systems using POKEY sound chip
SPC 	Super Nintendo/Super Famicom
VGM/VGZ 	Sega Master System/Mark III, Sega Genesis/Mega Drive,BBC Micro

Features:

    Can be used in C and C++ code
    High emphasis has been placed on making the library very easy to use
    One set of common functions work with all emulators the same way
    Several code examples, including music player using SDL
    Portable code for use on any system with modern or older C++ compilers
    Adjustable output sample rate using quality band-limited resampling
    Uniform access to text information fields and track timing information
    End-of-track fading and automatic look ahead silence detection
    Treble/bass and stereo echo for AY/GBS/HES/KSS/NSF/NSFE/SAP/VGM
    Tempo can be adjusted and individual voices can be muted while playing
    Can read music data from file, memory, or custom reader function/class
    Can access track information without having to load into full emulator
    M3U track listing support for multi-track formats
    Modular design allows elimination of unneeded emulators/features 

This library has been used in game music players for Windows, Linux on several architectures, Mac OS, MorphOS, Xbox, PlayStation Portable, GP2X, and Nintendo DS.