Prevent creating an event queue when calling ms_queue_pump() in audio_stream_stop() and video_stream_stop().

new implementation of ms_audio_diff() that gives clever results. It is much less sensitives to temporal shifts at the middle of the scanned audio segment.

Update qsa soundcard and mediastream api to be able to control audio output device in the playback filter

extend the concept of IO descriptors for defining local input/output of AudioStream and VideoStream.
Big cleanup and rename many functions that were not following the usual conventions of mediastreamer2.

Use void* for window ids so that pointers can be passed on 64 bits architectures where the unsigned long is 32 bits (Windows 64 bits).