Expose functionality to emit custom entity events.

source/Entity/Vehicle.hpp

@@ -175,6 +175,11 @@ public:
     */
     void BindEvent(Int32 evid, Object & env, Function & func) const;
 
+    /* --------------------------------------------------------------------------------------------
+     * Emit a custom event for the managed entity
+    */
+    void CustomEvent(Int32 header, Object & payload) const;
+
     /* --------------------------------------------------------------------------------------------
      * See if the managed vehicle entity is streamed for the specified player.
     */