Create audio file for all sound effects.

Add:
	src/audio.c
		-will handle all audio calls; currently uses a bad hack-around
		(a system() call), but will ultimately implement ALSA or
		something comparable.

	src/audio.h
		-contains macros for sounds and their respective file paths
		(e.g. 'JUMP "res/audio/jump.wav"').

Mod:
	src/termcrate.c
		-replace system() audio calls with the audio() function from
		src/audio.c.