Fix various problems with the timer code. * SDL_timer_running wasn't always updated correctly. * Fixed occasional crash in SDL_SetTimer() when clearing threaded timers * It was possible to get both the timer thread and event thread running * Other misc. cleanup

## Makefile.am for SDL using the OSS /dev/dsp standard sound driver

noinst_LTLIBRARIES = libaudio_dsp.la
libaudio_dsp_la_SOURCES = $(SRCS)

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