contrib/opie: Sync with FreeBSD, but not much to see here.

contrib/opie: Sync with FreeBSD, but not much to see here.

A couple of bugfixes:

* Fix the overflow check in challenge handling (off by 1).

* Store all hashes in little endian format before folding to 64 bits, per
  RFC 2289. SHA1 code is big endian, so a bswap32() is needed.

* Create /etc/opiekeys with 0600, not 0644.

* Increase OPIE_HASHNAME_MAX for SHA1.

* Fix a buffer overflow in an unused file.

* Remove two unused (and empty) files.

The rest is just cosmetics.