Added a new header file: SDL_loadso.h It contains the following functions: SDL_LoadObject(), SDL_LoadFunction(), SDL_UnloadObject() The UNIX esd and arts audio code use these to dynamically load their respective audio libraries.

## Makefile.am for SDL using the UNIX /dev/audio sound driver

noinst_LTLIBRARIES = libaudio_sun.la
libaudio_sun_la_SOURCES = $(SRCS)

# The SDL audio driver sources
SRCS =	SDL_sunaudio.c	\
	SDL_sunaudio.h