Request Helper Extension and Authorise Update

This updated Release Candidate for 0.3.0 adds some further functionality which became obvious when running integration tests.

Added two methods to the new Request Helper class getTokenHeader() and getTokenPayload() which make it easier to work with tokens stored in the request object.

Also renamed the core Authenticate class to Authorise as this is far more accurate in regards to the domain. Apologies for the English spelling. ;)

Added some comments, extra tests and general tidy up.