po: set gettext domain in Makevars so we don't have to patch the generated Makefile.in.in

https://bugzilla.gnome.org/show_bug.cgi?id=705455
Automatic update of common submodule

From dbedaa0 to d48bed3
Merge remote-tracking branch 'upstream/master' into ruih/master
Merge pull request #5 from cablelabs/merge-2013-12-23

Merge 2013 12 23