when removing element, remove from name collision check
when removing element, remove from name collision check

Previously if you add and remove object, you can no longer
add object with same short-name, because system thought
there is already object like that.

atk4/atk4,atk4/atk4,atk4/atk4,atk4/atk4,xepan/atk4,svisystem/atk4,xepan/atk4,xepan/atk4,svisystem/atk4,svisystem/atk4