Update for gnome control center 3.6, bnc#803195

Please see https://bugzilla.novell.com/show_bug.cgi?id=803195

This is a candidate for a version update but no bump is yet applied.

* configure.in.in: now requires x11
* src/cut-n-paste/: update code from gnome-control-center
* src/{control-center.c,gnome-control-center.c,shell.ui}: rebase on updated code
* src/patch/: update patch to current changes