- (dtucker) [openbsd-compat/getopt.c] Factor out portibility changes to
   getopt.c.  Preprocessed source is identical other than line numbers.
 - (dtucker) [openbsd-compat/getopt_long.c] Import from OpenBSD.  No
   portability changes yet.
 - (dtucker) [openbsd-compat/Makefile.in openbsd-compat/getopt.c
   openbsd-compat/getopt_long.c regress/modpipe.c] Remove getopt.c, add
   portability code to getopt_long.c and switch over Makefile and the ugly
   hack in modpipe.c.  Fixes bz#1448.
- (dtucker) [openbsd-compat/getopt.h openbsd-compat/getopt_long.c
  openbsd-compat/openbsd-compat.h] pull in getopt.h from openbsd and plumb
  in to use it when we're using our own getopt.
 - (dtucker) [kex.c] Only include sha256 and ECC key exchange methods when the
   underlying libraries support them.
 - (dtucker) [configure.ac] Add -Werror to the -Qunused-arguments test so
   we don't get a warning on compilers that *don't* support it.  Add
   -Wno-unknown-warning-option.  Move both to the start of the list for
   maximum noise suppression.  Tested with gcc 4.6.3, gcc 2.95.4 and clang 2.9.