* private.h, zdump.c (TZ_DOMAIN): Look at HAVE_GETTEXT,

not TZ_DOMAINDIR, when deciding whether to define.  This fixes a
recently-introduced typo.  Found by compiling with -DHAVE_GETTEXT
under GNU/Linux.
Fix some 'zic' issues when run as root.

* zic.c: Use angle brackets for <sys/stat.h>.
(dolink): Don't try to link from a directory, as this can
cause trouble on some systems when superuser.
(dolink, itsdir): Rewrite to avoid use of 'access', which is
problematic when setuid.
(itsdir): If S_ISDIR is defined, use plain 'stat' and S_ISDIR;
that's more reliable.  Return -1 if trouble; all callers changed.
(mkdirs): Simplify by using mkdir-itsdir rather than
itsdir-mkdir-itsdir.  Don't assume strerror preserves errno.