The previous code just printed time_t directly with "%ld". Now it
instead first casts to time_print_T (currently long) and then formats
with TIME_PRINT_FORMAT (currently "ld"). So the varargs will now
always match with the format string, even if time_t is longer than
long. This still doesn't correctly format time_t values larger than
LONG_MAX, though. But now it is at least easier to find some of the
places that need to be changed to support that.
I located these time_t-to-string conversions by searching for
str_to_time_t, expires, and last_visit. There are still more places
that assume every interesting time_t value fits either in 32 bits or
in a long, e.g. in the cookie editor and in the ECMAScript interface.
Inspired by bug 6.
Introduce a new list, global_history_reap_list, and a new routine,
reap_deleted_globhist_items, which deletes unused items from that
list. In done_global_history_item, do not free the item; just move it
to that list. Call global_history_reap_list in add_global_history_item
and free_global_history.
