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.
@Fiero99 I actually managed to write an iterative version that has a single while loop and a single for loop in two different methods (so that the nesting within each method is at most one level deep). I tested its behavior through play-testing and it appears to work as expected.