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 the AmigaOS joystick driver for SDL

noinst_LTLIBRARIES = libjoystick_amiga.la
libjoystick_amiga_la_SOURCES = $(SRCS)

# The SDL joystick driver sources
SRCS =  SDL_sysjoystick.c