Update defintion of validity for ReceiptFreeness
update the validity for the simulator
Add bisim to Control.Strategy.Utils
split up Game.ReceiptFreeness.Definitions in more modules
Add Control.Protocol.* features for describing games
Add Protocol version of IND-CCA2-dagger
Add Protocol version of ReceiptFreeness
Add a simulator for ReceiptFreeness and CCA2d using Protocols
Add a generalised version of CCA2 using Protocol