* dirmngr/dirmngr.c (HOUSEKEEPING_INTERVAL): New.
(housekeeping_thread): New.
(handle_tick): Call new function.
* dirmngr/ks-engine-hkp.c (RESURRECT_INTERVAL): New.
(struct hostinfo_s): Add field died_at and set it along with the dead
flag.
(ks_hkp_print_hosttable): Print that info.
(ks_hkp_housekeeping): New.
--
The resurrection gives the host a chance to get back to life the next
time a new host is selected.