- Only once set notBefore to "now" when creating Cert-renewal
or NewCert dialog.
- Apply-time button now always uses the current value from notBefore
and adds the time-span without resetting notBefore
- Checking "midnight" now immediately modifies the dates.
Unchecking "midnight" now recovers the old value
- The seconds are always set to 00, since they can't be set via
the DateTime dialog anyway
- CRL generation now too allows to use midnight and time ranges
and uses GENERALIZED time if the date is out of range for UTCTIME
(same logic as for certificates)