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

#ifndef _SDL_SYSMUTEX_C_H_
#define _SDL_SYSMUTEX_C_H_

struct SDL_mutex {
	pth_mutex_t mutexpth_p;
};

#endif /* _SDL_SYSMUTEX_C_H_ */