Set line-width, point size when running callbacks

Since 2.76 Blender no longer resets these after use,
this may break add-ons, so reset before calling region callbacks.

source/blender/editors/include/UI_interface.h

@@ -776,6 +776,7 @@ void UI_popup_handlers_remove_all(struct bContext *C, struct ListBase *handlers)
 void UI_init(void);
 void UI_init_userdef(void);
 void UI_reinit_font(void);
+void UI_reinit_gl_state(void);
 void UI_exit(void);
 
 /* Layout