different bugs and issues
-------------------------
- sometimes a deadlock occurs in deinitialization done by the signal handler
- fix late software fallback for emulated triangles and clipping in some cases


LSB violations
--------------

http://www.linuxbase.org/spec/gLSB/gLSB/libpthread.html

- Applications must disconnect from the controlling tty before calling
  pthread_create.

- Threaded applications cannot use SIGUSR1 or SIGUSR2.


demo problems
-------------
- some demos work incredible slower with hardware drivers that do not support
  every blitting function (all except matrox) than with the generic driver. 
  This is because the surfaces are loaded into offscreen video memory, but
  cannot be blitted by hardware afterwards because of the non-supported
  blitting effects (modulation etc). All demos should query the hardware
  drivers' capabilities, and decide where the surfaces should go.
