Crash / Unexpected behavior when changing device during playback

[andulv]

Cause: Destroys / Recreates rendererinstance when other thread(s) are feeding data to it.

Also: Media Type negotiation is based on the device's supported formats. When the device changes the agreed media type may no longer be valid.

Easiest solution: Deny changing of audio device when connected.

[andulv]

Workaround: Stop playback and disconnect filter before changing device.