compositor: Fold the log prototypes into compositor.h and drop log.h

We're trying to keep the API exposed by the core compositor in compositor.h

src/xwayland/launcher.c

@@ -34,7 +34,6 @@
 
 #include "xwayland.h"
 #include "xserver-server-protocol.h"
-#include "../log.h"
 
 
 static int

src/xwayland/selection.c

@@ -28,7 +28,6 @@
 #include <fcntl.h>
 
 #include "xwayland.h"
-#include "../log.h"
 
 static int
 weston_wm_write_property(int fd, uint32_t mask, void *data)

src/xwayland/window-manager.c

@@ -37,7 +37,6 @@
 
 #include "../../shared/cairo-util.h"
 #include "../compositor.h"
-#include "../log.h"
 #include "xserver-server-protocol.h"
 #include "hash.h"