-Changed Godot exit to be clean.

-Added more debug information on memory cleanliness on exit (if run with -v)
-Fixed several memory leaks, fixes #1731, fixes #755

tools/editor/plugins/spatial_editor_plugin.h

@@ -224,6 +224,7 @@ private:
 	void _preview_exited_scene();
 	void _toggle_camera_preview(bool);
 	void _init_gizmo_instance(int p_idx);
+	void _finish_gizmo_instances();
 
 
 protected:
@@ -324,6 +325,8 @@ private:
 	RID indicators_instance;	
 	RID cursor_mesh;
 	RID cursor_instance;
+	RID indicator_mat;
+	RID cursor_material;
 
 /*
 	struct Selected {