Update to 3.6.1

[IMPACT]

This is needed for the gnome-shell 3.6.1 update (LP: #1067145)

Bug 648156 below sounds especially interesting as it may significantly help multi-monitor support for GNOME Shell users.

http://git.gnome.org/browse/mutter/tree/NEWS

* Fix crash when opening large popup menus [Jasper; #681676]
* window: Don't move the desktop window after monitor hotplug [Jasper; #681159]
* Expose MetaPlugin to introspection [Evan; #671098]
* Optionally delay focus changes in focus-follows-mouse mode [Florian; #678169]
* Resize the guard window when the X screen is resized [Benjamin; #670396]
* display: Only manage the default X screen [Jürg; #648156]
* Misc cleanups: [Owen; #587255]

 * An explanation of the of the bug on users and

 * justification for backporting the fix to the stable release.

 * In addition, it is helpful, but not required, to include an
   explanation of how the upload fixes this bug.

[TESTCASE]

 * Basically, just make sure gnome-shell still works as expected.

[Regression Potential]

* This could break gnome-shell but that seems rather unlikely.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: mutter 3.6.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.5.0-17.28-generic 3.5.5
Uname: Linux 3.5.0-17-generic x86_64
ApportVersion: 2.6.1-0ubuntu3
Architecture: amd64
Date: Mon Oct 15 22:09:28 2012
SourcePackage: mutter
UpgradeStatus: No upgrade log present (probably fresh install)