Changes for DateTime-Event-ICal

0.01    2003-05-23
- tests all expressions mentioned in RFC2445
- bysetpos is 2x faster
- fixed the order of operations: bysetpos x span

0.00_02    2003-05-12
- bysetpos
- count
- by(units)

0.00_01
- base implementation:
  until, interval, dtstart, dtend, until