majalan

Copperbox revision 2929.

I've changed the implementation of EventList to use a datatype representing state rather than pass the two parts of state as separate arguments (the result always had to combine them of course). This is a prelude to making the onset times of events in a notelist relative rather than absolute. With relative onset times it is easy to repeat a notelist after itself - all we have to do is shift the initial onset time of the repeated notelist.