Do not use knowledge about the FFmpeg version in transcode.

With the mutex patch plus a few fixes.
Signed-off-by: Rémi Denis-Courmont <rdenis@simphalempin.com>

This could trigger some interface bugs, especially if they handle their callbacks carelessly. Revert if you have issues, but also consider to fix your interface.

libvlccore: "intf-show" is now a libvlc var instead of a playlist var. This removes a vout->playlist dependency.

Add ENABLE_NLS define, and make po files optional
Update source files to latest modifications
Add missing function checks
Define QT4LOCALEDIR
Require ncurses (I will submit a patch to cmake to check for ncursesw)

Note that an upper limit should be set anyway

This reverts commit e31c7798.

Damned, this is a hack to display psz_cat in the playlist.

So that vlc --{list,help,module} don't get us a non-null exit code

(cherry picked from commit a2d82490555eb3271a77b4958bc8528091951901)

Conflicts:

	modules/control/rc.c

/!\ In pure C, `()` means `(...)`, not `(void)`