Quartz driver OpenGL updates: Driver can now open whatever library is specified in SDL_GL_LoadLibrary() call (previously, it ignored this parameter), and uses the default system library when NULL is specified. Also, library is loaded once in SDL_GL_LoadLibrary() and not every call to SDL_GL_GetProcAddress().

## Makefile.am for SDL using the Win32 DirectX audio driver

noinst_LTLIBRARIES = libaudio_windx5.la
libaudio_windx5_la_SOURCES = $(SRCS)

# The SDL audio driver sources
SRCS =	SDL_dx5audio.c	\
	SDL_dx5audio.h