(Suggestion) Alter portcullises so they can't be exploited.

[JiFish]

Currently portcullises can be exploited for unlimited blocks, particularly iron bars.

Suggestions to resolve:

1. Have all portcullises start closed and remove the close buttons.

2. Eliminate iron bar portcullises.

3. At minimum put a warning in the config

Anecdotal: My group never closed them, thinking one button was just 'dud'. As soon as they realised they were close buttons, they thought of this exploit. (I hadn't even considered it.) But then they are a smart bunch.

[orphu]

I actually like option 1