Dependency Updates and Base64 Encoding protection

added protection for issue #164 so it is obvious as to why waffle dislikes unexpected authentication headers.

Updated jetty and tomcat versions.

Some minor code enhancement seen while looking around for good type of error to use for the encoding issue fix based on logic of waffle.

Removal of deprecated base64 used in waffle 1.6 and earlier.

Keeping on the maven dependency update train!
I almost feel like this should be a specialized exception, but it's not a big deal.