Really fixes #1051

Fixes #1051

Add option to specify which muxer we want to use in ffmpeg (ie: #std{mux=ffmpeg{mux=flv}...) Still seems kind of broken as the resulting file can't be demuxed by vlc/libavformat. Looks like the video and audio codec aren't identified correctly in the ffmpeg muxer. Must be some error in mux.c i guess.

That being said, I either don't understand sout chain (likely) or
it is plain broken (unlikely) but I can't seem to pass parameters
to the access output.

Fix #1048... kind of. Should the rc interface be able to accept more than 1 connection ? and accept tcp connections + stdin commands ? (currently only 1 connection can be active)

(this is a revert of ffmpeg [7589])

* fixed a bug which prevented the fspanel to show up in some circumstances. Patch by Pierre d'Herbemont pdherbemont --at,- free.fr. This commit priortises Cocoa hotkeys instead of VLC's natives which is a good idea IMO.