Fix gsettings path to use /org/gnome instead /apps

[Luca Ferretti <lferrett gnome org>]

Flash news from release team to our all brave developers.

A member of release team known as *cough*Luca Ferretti*cough* was sure
gsettings PATHs and gsettings IDs were the same, so he was also sure all
GNOME 3 core apps were using the proper path. So he never sent any
notice or filed bug report...

But we don't want to blame his errors, we want to have a fine tuned
GNOME 3 Desktop. A quick grep[1] shows about 15 basic modules using the
wrong PATH. Patches are available here[2][3]. 

No string changes, no code changes, no UI changes (except paths showed
in dconf-editor, but this is totally undocumented by now), and hard code
freeze exception yet pre-approved.

If you have no time to commit, I'll be glad to help you, just ask on irc
(elle.uca) or reply here.

Next step: do the same on non-core modules, but I suppose we can work on
it during 3.2 timeline.

Cheers, Luca

[1] http://paste.ubuntu.com/584321/
[2] http://people.gnome.org/~lferrett/patch/
[3] actually it misses a patch for org.gnome.packagekit.gschema.xml