Orders Part 4 and a bugfix

still a while away from being able to issue an order to do anything
other than move, but the new orders class should provide what I need to
accomplish that. Likewise I modified Commander to add the logisticsBonus
statistic, and add the ability for populations and ships to have
commanders, as well as be marked as uncommanded. Finally I refactored
several enum types that I had been using, and moved them over to
constants.cs

Also I found a bug with my linked lists and corrected that.