ldns: Update vendor branch from 1.6.11 to 1.6.16
Merge branch 'vendor/LDNS'
libldns, drill(1): Update to version 1.6.16

Many dports that require libldns were not building because the library
was detected, but not the ldns.h header (along with its 30+ friends).
The headers were available in contrib, but not installed.  However, the
version 1.6.11 is too old for at least some of the ports, so it became
necessary to update LDNS to the latest version.
Some manual page fixes here and there.

It also reverts most of the changes done to tzfile.5 with the
"locale megapatch". Ours was in sync with upstream's tzcode2012c, while
FreeBSD uses tzcode2009e. There's probably more work to bring back in
libc/stdtime.
Fix two section references in hammer and jail manpages.
newlocale.3: Fix header file name.
wmemchr.3: Add missing const to prototypes.
iswalnum_l.3: Fix prototypes.