Support including floor thinkness for interzonalairflowtype.TwoPort

[kldjonge]

In light of a discussion we had at our research group I would like to add support that considers the floor thinkesses better. Now the input for hZone is a bit confusing (especially in the rectangular zone template). As hZone should be the internal room height, it means that the thinkness of the floors are ignored for internal stack-effect OR one should be very mindfull about the habsfloor parameter and dissable the vertical height check.

I'm working on a solution.

[kldjonge]

@jelgerjansen, I opened a new issue for this because a decent implementation will alter the reference results.

[jelgerjansen]

Closed by #1435