Replace (and auto-upgrade) ctrl/time.dab with time.ini

This will allow us to change scfg_t.event[].last to a time_t value (from
time32_t) whenever we abandon Borland C/C++ in the future.

Now it's trival for sysops to view/edit when their timed events 'last run'
values. And there's no more endianness concerns. Bad .dab files, bad, go away.

After I wrote this change, I found the original conversion code in v4upgrade.c
which is almost exactly the same (except I was going to write to different
filename). Finally actually implemented this. Next up: qnet.dab