script: Add loading from a resource

GLib has gained support for compiling ancillary data files into the same
binary blob as a library or as an executable.

We should add this feature to ClutterScript, so that it's possible to
bundle UI definitions with an application.

clutter/clutter-script.h

@@ -153,6 +153,9 @@ guint           clutter_script_load_from_data           (ClutterScript
                                                          const gchar               *data,
                                                          gssize                     length,
                                                          GError                   **error);
+guint           clutter_script_load_from_resource       (ClutterScript             *script,
+                                                         const gchar               *resource_path,
+                                                         GError                   **error);
 
 GObject *       clutter_script_get_object               (ClutterScript             *script,
                                                          const gchar               *name);