Bugs and a fix

Hi,

I've fixed another bug (and added a test for that) and replaced CreateHashKey by using EntityKeys. 

I also added a failing test which I had no luck trying to fix. The setup is actually quite simple: just an entity with an associate but both (entity and associate) also are part of a 'group' which in turn is associated to both of them (thus creating a cycle). And that's where it fails. The ObjectStateManager complains that it can't track two entities with the same key as soon as the second entity is attached (because it contains an indirect reference to the first which has already been attached). I think it may not be correct to have AttachAndReload attach the whole sub graph (should only be the entity itself) but I couldn't think of a way to implement that properly. 

Also I just realized that I somehow screwed the line endings in some files up. Just not my day, today..