freeze break request: gnome-shell and mutter

[Colin Walters <walters verbum org>]

Hi,

The basic bug is that if a developer builds gnome-shell and does
./src/gnome-shell --replace from the source tree, you will get a fail
whale dialog.

The fix is here:
gnome-shell: https://bugzilla.gnome.org/show_bug.cgi?id=645593
mutter: https://bugzilla.gnome.org/show_bug.cgi?id=645590

They are quite simple patches; I am confident of low chance of regression.