Signaling an event ensures that at least one thread wakes up, but it
does not warrant that all of them do.

(No functional changes)

This avoids SIGPIPE firing when writing to a remote-closed connection-
oriented socket (it is useless for datagram sockets or on Windows
though). SIGPIPE is blocked ins VLC, but not necessarily in LibVLC.

The problem remains for write() on broken pipe and sockets.

Removes singleton, fixes initialization and deletion. Renames to
AddonsWindowController.

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.