Restructuring glue code to make it easier to extend

platform/android/java/src/org/godotengine/godot/Godot.java

@@ -606,6 +606,9 @@ public class Godot extends Activity implements SensorEventListener, IDownloaderC
 		for (int i = 0; i < singleton_count; i++) {
 			singletons[i].onMainDestroy();
 		}
+
+		GodotLib.ondestroy(this);
+
 		super.onDestroy();
 	}
 

platform/android/java/src/org/godotengine/godot/GodotLib.java

@@ -46,6 +46,7 @@ public class GodotLib {
      */
 
 	public static native void initialize(Godot p_instance, Object p_asset_manager, boolean use_apk_expansion);
+	public static native void ondestroy(Godot p_instance);
 	public static native void setup(String[] p_cmdline);
 	public static native void resize(int width, int height);
 	public static native void newcontext(boolean p_32_bits);