Since audio-channels was not a configuration item, renaming is a mere
internal matter. This also fixes callback handling and factors code.

(fix #7537)

If the calling thread is using COM with MTA model, then CoInitializeEx()
will fail, and CoUninitialize() will be unbalanced. Ultimately, the
calling thread is likely to crash. (CoInitializeEx() could also fail in
case of memory error, but that is unlikely).

pshufb is available with SSSE3, not with SSE3

This should fix resizing for all (one-)vout-window variants.
Furthermore, this fixes a small bug regarding aspect ratio enforcement.

refs #6814

The main window may be asked to update its content prior to VLCFSPanel being fully initialized

Some filters and outputs rely on the samples count (which was correct),
others on the bytes size (which was not), accounting for why decoding
failed only in some combinations.

That is recommended by MSDN. Also, do not use 0 for NULL.

It is not needed anymore since ce652138 , parsing will
stop at first unrecognized character (like \r or \n)

This affects: .opus, .ogx, .wtv, .rec, .vro, .tod and .mks

This avoids grey or transparent flashes on start

Note that this commit will break some stuff for non-embedded cases, for now.

refs #6814