Start creating different subdirectories for each backend

src/backends/meta-backend.c

@@ -31,7 +31,7 @@
 #include <clutter/clutter.h>
 #include <clutter/x11/clutter-x11.h>
 
-#include "meta-weston-launch.h"
+#include "backends/native/meta-weston-launch.h"
 
 /* Mutter is responsible for pulling events off the X queue, so Clutter
  * doesn't need (and shouldn't) run its normal event source which polls

src/backends/meta-idle-monitor.c

@@ -38,8 +38,8 @@
 #include <meta/meta-idle-monitor.h>
 #include "meta-idle-monitor-private.h"
 #include "meta-idle-monitor-dbus.h"
-#include "meta-idle-monitor-xsync.h"
-#include "meta-idle-monitor-native.h"
+#include "backends/x11/meta-idle-monitor-xsync.h"
+#include "backends/native/meta-idle-monitor-native.h"
 
 G_STATIC_ASSERT(sizeof(unsigned long) == sizeof(gpointer));
 

src/backends/meta-monitor-manager.c

@@ -36,8 +36,8 @@
 #include "util-private.h"
 #include <meta/errors.h>
 #include "meta-monitor-config.h"
-#include "meta-monitor-manager-kms.h"
-#include "meta-monitor-manager-xrandr.h"
+#include "backends/native/meta-monitor-manager-kms.h"
+#include "backends/x11/meta-monitor-manager-xrandr.h"
 #include "meta-monitor-manager-dummy.h"
 
 enum {