NF: MazeItems.
NF: Experimental cabal config.
ENH: Use zeromq4.
ENH: Update to monadic zmq interface.
RF: ‘server’ → ‘sock’.
ENH: ScopedTypeVariables
RF: Some refactoring.
RF: State monad preparations.
RF: State monad preparations.
ENH: State Monad.
RF: Some cleanup.
FO: Style.
ENH: Verbose testing player.