Add temporary cogl-clutter.h to aid splitting out Cogl

This gives us a way to clearly track the internal Cogl API that Clutter
depends on. The aim is to split Cogl out from Clutter into a standalone
3D graphics API and eventually we want to get rid of any private
interfaces for Clutter so its useful to have a handle on that task.
Actually it's not as bad as I was expecting though.

cogl/cogl-clutter.c

@@ -0,0 +1,59 @@
+/*
+ * Cogl
+ *
+ * An object oriented GL/GLES Abstraction/Utility Layer
+ *
+ * Copyright (C) 2011 Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Authors:
+ *   Robert Bragg <robert@linux.intel.com>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <glib.h>
+
+#include "cogl.h"
+#include "cogl-types.h"
+#include "cogl-private.h"
+#include "cogl-context-private.h"
+#include "cogl-winsys-private.h"
+#include "cogl-framebuffer-private.h"
+
+gboolean
+cogl_clutter_check_extension (const char *name, const char *ext)
+{
+  return _cogl_check_extension (name, ext);
+}
+
+void
+cogl_onscreen_clutter_backend_set_size (int width, int height)
+{
+  CoglFramebuffer *framebuffer;
+
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  if (!ctx->stub_winsys)
+    return;
+
+  framebuffer = COGL_FRAMEBUFFER (ctx->window_buffer);
+
+  _cogl_framebuffer_winsys_update_size (framebuffer, width, height);
+}