Port preferences to GSettings

Move preferences to GSettings, using mainly shared schemas from
gsettings-desktop-schemas.

Unlike GConf, GSettings support is not optional, as Gio is already
a hard dependency of GTK+.

https://bugzilla.gnome.org/show_bug.cgi?id=635378

src/meta/common.h

@@ -1,6 +1,9 @@
 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
 
-/* Mutter common types shared by core.h and ui.h */
+/* Mutter common types shared by core.h and ui.h
+ *
+ * PLEASE KEEP IN SYNC WITH GSETTINGS SCHEMAS!
+ */
 
 /* 
  * Copyright (C) 2001 Havoc Pennington
@@ -164,32 +167,6 @@ typedef enum
 
 } MetaCursor;
 
-typedef enum
-{
-  META_FOCUS_MODE_CLICK,
-  META_FOCUS_MODE_SLOPPY,
-  META_FOCUS_MODE_MOUSE
-} MetaFocusMode;
-
-typedef enum
-{
-  META_FOCUS_NEW_WINDOWS_SMART,
-  META_FOCUS_NEW_WINDOWS_STRICT
-} MetaFocusNewWindows;
-
-typedef enum
-{
-  META_ACTION_TITLEBAR_TOGGLE_SHADE,
-  META_ACTION_TITLEBAR_TOGGLE_MAXIMIZE,
-  META_ACTION_TITLEBAR_TOGGLE_MAXIMIZE_HORIZONTALLY,
-  META_ACTION_TITLEBAR_TOGGLE_MAXIMIZE_VERTICALLY,
-  META_ACTION_TITLEBAR_MINIMIZE,
-  META_ACTION_TITLEBAR_NONE,
-  META_ACTION_TITLEBAR_LOWER,
-  META_ACTION_TITLEBAR_MENU,
-  META_ACTION_TITLEBAR_LAST
-} MetaActionTitlebar;
-
 typedef enum
 {
   META_FRAME_TYPE_NORMAL,
@@ -374,10 +351,8 @@ void meta_frame_borders_clear (MetaFrameBorders *self);
 
 /* G_PRIORITY_DEFAULT_IDLE:
  *  Mutter plugin unloading
- *  GConf notify idle
  */
 
-/* Chosen to be below the GConf notify idle */
 #define META_PRIORITY_PREFS_NOTIFY   (G_PRIORITY_DEFAULT_IDLE + 10)
 
 /************************************************************/