move zone data loading entirely into ztree_init()
Remove arbitrary 64 addr limit from multifo

This was leftover from 1.x before the structures were changed to
allow larger dynamic sets.  The new limits are higher and enforced
elsewhere.
whitespace: kill some tabs that slipped in
add missing PHONY for t/Makefile.am:precheck
vscf: use dmn_log_err directly

The avoidance of it was primarily because vscf used to be a
separate library project with a more general focus.  At this point
I don't see the vscf code ever escaping the confines of the
private libgdnsd, and this simplifies some other integrations.
de-duplicate readonly mmap code to gdnsd_fmap_*()

vscf, rfc1035, and the libgdmaps GeoIP1 code were all using slight
variations on the same basic "mmap a file for reading" theme, and
they were all less-than-ideal.

Aside from basic de-duplication and cleanup, this new variant also
adds O_CLOEXEC and advisory fcntl() readlocks for them all.
zsrc_rfc1035: refactor/improve change detection

The most important change here is that the code no longer tries to
heuristically determine the filesystem timestamp accuracy of the
zones directory via test writes at startup.

In general the code has been re-reviewed and updated to be more
resilient against certain kinds of races/failures when the user's
zonefile updates are atomic, and to expend less effort/time on
accomodating race-workarounds for non-atomic updates.

The expected normal cases of atomic updates and/or inotify()
should generally be more efficient and have lower latency than
before.

The zones_rfc1035_min_quiesce config option is gone (deprecation
warning on startup if set) and users can no longer configure
unportable/unreliable sub-second quiescence periods.  The code
still transparently uses sub-second timestamp information to help
avoid the worst fallouts from timestamp races, if available.