Heigh changer old style refactored

This is the old heightchanger but with only a little code cleanup. Comments inserted and javadoc added. I think, sasier than this is not possible using such a recursive function.
Yep, there IS an iterative approach for this. I have implemented this monday and tuesday, but this didn't work as well as this approach. We (Gijs, Thijs, Simon) discussed this over Skype yesterday and came to the conclusion that an iterative approach had to check an area of 50x50 tiles to acquire the same result. Because of this, we chose the stick on the iterative approach. With this iterative approach, the changeheight on slopes works a lot better.

And, unfortunately, no. I can't make this recursive function any easier than this..