WPP-57: v2 improvements

The following changes are proposed for the WPP v2:

1. CAS proxy bug fixes (serviceUrl, final proxy URL creation)
2. Switched the logging framework to just logback/slf4j
3. Fixed formatting issues in a number of Java classes
4. Added CAS proxy attribute
5. Fixed a bug in whitelist regex matching (blank regex forces the filter to rewrite everything)