Gtk3: Require mate-desktop 1.9.3
Gtk3: size-request signal is no more, use correct api
correctly destory enum_group
Revert "Gtk3: size-request signal is no more, use correct api"

This reverts commit 06a00876a690711437d30f7183595734298cd603.
Gtk3: size-request signal is no more, use correct api
zero-init signals array
use guint for signals array
don't leak memory
Adapt to API changes in MateRRScreen

gnome_rr_screen_new does not accept a callback anymore, we need
to use the "screen-changed" signal

Based on gnome-control-center commit: 66e8e903be8ad25fe3b1386d1fbda75359959e97
From: Giovanni Campagna <gcampagna@src.gnome.org>
Adapt to MateDesktop API changes

MateRRScreen, MateRRConfig and MateRROutputInfo (formerly
MateOutputInfo) have turned into opaque GObjects. Use accessors
for modifying them, and allocate/free them as GObjects.

Based on gnome-control-center commit: 3eb3ca4506624fb537c55796d1397eb5f9b8da4b
From: Giovanni Campagna <gcampagna@src.gnome.org>
Update for renamed mate_rr_output_info functions

mate_rr_output_info_get_connected -> mate_rr_output_info_is_connected
mate_rr_output_info_get_active -> mate_rr_output_info_is_active
Adapt to changed signal from screen-changed to changed
[displays] Change panel name to Displays

Monitors aren't the only use of this panel. Projectors and tablet screens don't involve monitors at all.

Based on gnome-control-center commit: e8b52610496818a214cf8b12d955cc4fca40f085
From: William Jon McCann <jmccann@redhat.com>
Bump required mate-desktop version for materr* changes
Update NEWS
fix build error that C++ users will stumble upon
removed unused var which also caused memleak
fix weird logic, prevent memleak
fix another little memleak by making logic cleaner
fix one more little memleak and make another logic cleaner