Fix ecpg -? option on Windows, add -V alias for --version.

This makes the -? and -V options work consistently with other binaries.
--help and --version are now only recognized as the first option, i.e.
"ecpg --foobar --help" no longer prints the help, but that's consistent
with most of our other binaries, too.

Backpatch to all supported versions.

Haribabu Kommi

Discussion: <CAJrrPGfnRXvmCzxq6Dy=stAWebfNHxiL+Y_z7uqksZUCkW_waQ@mail.gmail.com>