EAP-pwd: Fix some interoperability issues

EAP-pwd: Fix some interoperability issues

The changes are:

  1. the word "and" in the hunting-and-pecking string passed to the KDF
     should be capitalized.
  2. the primebitlen used in the KDF should be a short not an int.
  3. the computation of MK in hostap is based on an older version of the
     draft and is not the way it's specified in the RFC.
  4. the group being passed into computation of the Commit was not in
     network order.