refs #14649

Removes sharedInstance from About window controller, and rework
as a NSWindowController subclass. This is the new owner of the xib
and thus instantiated outside the nib bundle.

Splits Help window in own xib and add own NSWindowController as
well.

refs #5556

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

The CSD is now split into several ones, therefore there is one CSD per H264
Parameter Sets (SPS and PPS).

There is now only one way to send a CSD. It's sent via PutInput with the
BUFFER_FLAG_CODEC_CONFIG flag.

Do only MediaCodec specific in PutInput.

None of the call sites use the input thread and wait pipe.