Turn MateRRConfig and MateOutputInfo into GObjects

Based on gnome-desktop commit 1d1f8ef64f404eccb29d384a75939701327e8e77
From: Giovanni Campagna <gcampagna@src.gnome.org>
Remove scrollkeeper option from DISTCHECK_CONFIGURE_FLAGS
introspection: A few fixes from gnome-desktop.

Commit: 446e8ffcf16ccf909f45b293532f50996b0dd728
Fix c-includes to actually include headers
From Benjamin Otte <otte@redhat.com>

Commit: b13ecfd8d5197d4ffac649f5e443a432021e50ad
include exported pkg-config name in GIR
Evan Nemerson <evan@coeus-group.com>
Fix distcheck for introspection
Update GnomeRRScreen

Based on gnome-desktop commit: 2c7a2e90fee98ff61e530098bc962a65dec670bc
From: Giovanni Campagna <gcampagna@src.gnome.org>

- store priv as a local variable
- chain up in finalize (this was actually a bug)
- make :gdk-screen readwrite
- add a ::changed vmethod for the signal
- remove the callback in gnome_rr_screen_new, and drop mate_rr_screen_destroy