This plan implements the initiator of the "FIPA Dutch Auction Interaction
Protocol Specification" (XC00032 - Experimental)
A dutch auction is one where the auctioneer starts with a high start price
and continually lowers it until the first bidder accepts the price.
A helper class that handles a receiver side goals
of the iterated contract net protocol by delegating
to some implementation of the corresponding interface.
An object containing information about
a proposal made in a negotiation, i.e.,
the component identifier of the participant
and the content object of the proposal
message.