the `pw_expire'
(ka_convert): set `valid_end' from ka expiration data and `pw_expire'
from pw_change + pw_expire
(main): add a default database for ka dumping
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@7996 ec53bebd-3082-4978-b11e-865c3cabbd6b