* modules/audio_output/directx.c: fixed the "no sound on NT4" problem. The directx audio plugin wasn't freeing its resources properly in case Probe() failed so the waveout plugin couldn't open the audio device afterwards.
* modules/video_output/directx/directx.c: work-around buggy video drivers that create unsupported surfaces without shouting. Hopefully, non overlay YUV surfaces shouldn't be created anymore if not supported.