Added the BuyBehaviour class that first starts a query on the DF to find all agents that sell the specified part. Then the new HandleDFInform behaviour handles the resulting INFORM message with the results and selects the cheapest auction and sends a Bid message to the selling agent. If the lowest price is still too high the BuyBehaviour stops. A HandleBidResponse behaviour is started to handle the response. If the seller disapproves the Bid the BuyBehaviour is restarted.