kinit should save cc configs if it krb5_cc_move()s

Also, renew_validate() should krb5_cc_new_unique() and krb5_cc_move() it
into place.
kinit cmd: back-off more slowly and warn

Also refactor AFS klog code so we do it only once on renew.
Add SIGINFO support for kinit cmd

Use SIGUSR1 if there's no SIGINFO, so the code isn't dead.
Don't use "if (!ret)"
lib/hdb/db3.c:DB_open() needs to DB_close() more

Without this the KDC can trip the assert in DB_open().
Add [manual] test of kinit cmd

It's not ready to always be run.  First, it's slow.  Second, it tortures
the system.  Third, it doesn't look for signs of failure.  Fourth, if it
did it'd fail: because something about the racing is causing the KDC to
think that the foo principal doesn't exist.