CASC-228 URL Encode Paramaters Passed to Server via Validate

Problem: We currently don't pass encoded values to the server, possibly resolving in parsing/extraction errors.
Solution: URL Encode all values instead of just the service url.

QA Notes: Added unit test.
Merge pull request #73 from battags/CASC-228

CASC-228 URL Encode Paramaters Passed to Server via Validate
CASC-224 Replace URL with String to remain compatible with Spring Security
Added missing license header.
[maven-release-plugin] prepare release cas-client-3.3.2
[maven-release-plugin] prepare for next development iteration