Changed order of parameters when creating StateTransitions with from state. Added direct support for just one support.
Added some documentation to StateTransition and StateMachine.
Rewrote StateTransition.GetHashCode to take null FromState or exceptions into account.
Removed StateMachine's AddTranstion(Predicate, State, State) and the corresponding RemoveTransition which are pretty pointless.
Added RemoveTransition(Transition) and RemoveTranstions(IEnumerable<Transtion>).