Authenticator class

The Authenticator class is the main part of the client library. This patch pre-release introduces the use of Token and InitVector classes.

Integration has been made with PHP.Gt/Session to allow for any object oriented session handler to be used, which allows for encapsulated session data storage. The decision has been made to design this library to still work with the standard PHP $_SESSION superglobal, which is especially useful for helping learning how Authwave works.