majalan

Copperbox revision 3013.

I've added an accumulating impulse map to the EventList structures - this should work in a similar manner to anchors in Wumpus (which in turn took them from TikZ).

I haven't yet tidied up the Answer type - a better thing to do looks like adding a general Writer-State monad instead. This should be a better opportunity to factor some code as all the EventList monads can be built with a Writer-State monad.