Replaced iteration text box with iteration combo box that shows the available iterations. Does not currently save the iteration to the requirement or retrieve the requirements iteration. The code for saving the iteration text box value and the listeners have been replaced with TODOs to be filled with the code for working with the combo box.
Merge branch 'dev-set3-iteration3' of https://github.com/333fred/wpi-suite-tng into dev-set3-iteration3