WSSE authentication method

Adding WSSE UsernameToken authentication system

More information @ https://d9db56472fd41226d193-1e5e0d4b7948acaf6080b0dce0b35ed5.ssl.cf1.rackcdn.com/committees/wss/documents/WSS-Username-02-0223-merged.pdf
I haven't found a doc file dedicated to authentication schemes and I think it's usefull to explain how nonce / date should be handled in the code.

Anyway, it would makes sense to create a specific doc page to explain how the basic authentication schemes should be implemented