Log Message:
update to roundup-0.6.4

Fixed:
- fixed date arithmetic to not allow day-of-month == 0 (sf bug 853306)
- fixed date arithmetic to limit hours-per-day to 24, not 60
- hard-coded python2.3-ism (socket.timeout) fixed
- fixed activity displaying as future because of Date arithmetic fix in
  0.6.3 (sf bug 842027).
- fix Windows service mode for roundup-server (sf bug 819890)
- fixed #white in cgitb (thanks Henrik Levkowetz)