Factoryfix is ready to merge!

@Tadimsky  @jo63  @wl88 @RFish6 

So the factory is pretty much 100%, or could be in a short amount of time. Producables and strategies for specific instances can be determined in the XML file. For now this only works for occupy because I thought we might change the constructors for the other strategies, but the others can be added in a matter of minutes. 
A design change I made was moving all the observer stuff and the List of producables up to InteractiveEntity (since both Units and Buildings can produce). Btw, we get a lot of duplicate code when we move stuff around like this because git re-adds all the deleted methods (that were moved) back. 
I don't know how we're going to integrate the factory but for now everything is stored in maps. If you want to 'get' something you can do myFactory.getResource("gold") or myFactory.getInteractiveEntity("soldier") for example. We'll probably move this to our managers later. 
Also added a few methods to ReflectionHelper.