Added unit test to accept hashes from different revisions.  See http://stackoverflow.com/questions/15733196/where-2x-prefix-are-used-in-bcrypt for difference between a, b, x and y.
Added unit test to accept hashes from different revisions.  See http://stackoverflow.com/questions/15733196/where-2x-prefix-are-used-in-bcrypt for difference between a, b, x and y.

neoKushan/BCrypt.Net-Core