chore, check for getline() and/or fgetln() in yuck.m4
fix, PEBKAC, use variable that actually exist
chore, also check for getline()/fgetln() in c.ac

tzmap.c needs that.
chore, kick getopt.h test and proto-header
minor, migrate ltrcc(1) helper to yuck
fix, PEBKAC, use variable names that actually exist
fix, mem-leak, free line-buffer resources in getline() case
minor, follow fgetln() semantics and check for length of buffered line
chore, define _NETBSD/_DARWIN/_ALL in tzmap.c so fgetln() gets decl'd
hygiene, operate on tzmap lines without modifying them
chore, define _NETBSD/_DARWIN/_ALL before stdio.h inclusion so fgetln() gets decl'd
minor, terminate zone string for error message
Merge branch 'bld/netbsd'

* bld/netbsd:
  minor, terminate zone string for error message
  chore, define _NETBSD/_DARWIN/_ALL before stdio.h inclusion so fgetln() gets decl'd
  hygiene, operate on tzmap lines without modifying them
  chore, define _NETBSD/_DARWIN/_ALL in tzmap.c so fgetln() gets decl'd
  minor, follow fgetln() semantics and check for length of buffered line
  fix, mem-leak, free line-buffer resources in getline() case
  fix, PEBKAC, use variable names that actually exist
  minor, migrate ltrcc(1) helper to yuck
  chore, kick getopt.h test and proto-header
  chore, also check for getline()/fgetln() in c.ac
  fix, PEBKAC, use variable that actually exist
  chore, check for getline() and/or fgetln() in yuck.m4