x11vnc: add dependencies for xrandr/xfixes/xdamage/xtst

Inspired by a patch by Martin Jansa but with these libraries required, as a VNC
server without them is suboptimal.  Don't add an option for Xinerama as our X
server always disables it.

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
clutter: fix compilation when building without X11 backend

If Clutter is building the Wayland backend but not the X11 backend, the Cogl
support doesn't get enabled so the Wayland backend (which uses it) fails to
compile.

Backport a fix from upstream to fix this situation.

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
weston: as weston-launch depends on PAM, control it with a PACKAGECONFIG

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>