gnome-settings-daemon patches

[Bastien Nocera <hadess hadess net>]

The most embarrassing bunch of patches you will ever see.

The a11y-settings plugin for gnome-settings-daemon (which monitors the
screen reader and On-Screen keyboard settings, and enables loading the
ATK GTK+ modules) was completely non-functional. This makes it work as
appropriate:
https://bugzilla.gnome.org/show_bug.cgi?id=645721

Related to this is:
https://bugzilla.gnome.org/show_bug.cgi?id=645708
which I have no intentions of committing for 3.0, as per bug.

Thanks for Frederic for his patience in testing my incomplete patches.