CAS-1438: URL matching support for proxy validation

https://issues.jasig.org/browse/CAS-1438

This commit in general intends to improve verification of service urls in terms of encoding and case upon validation requests. It presents the following changes:

1. An option for regex service to allow case-insensitive matching. By default case-sensitivity is turned on for backwards compatibility purposes.
2. When checking a ST to see if its issuance was against the same requesting service, the comparison of ids (urls) is now performed in a case-insensitive manner. Both ids (urls) are also first decoded before checking for equality in order to resolve encoding issues with %20, +, and likely other differences in encodig impls.
3. Test cases to cover all above scenarios.
Merge branch 'master' into CAS-1438

Conflicts:
	cas-server-core/src/main/java/org/jasig/cas/services/RegexRegisteredService.java
CAS-1438: regex svc matching to be case insensitive by default
Merge pull request #419 from Unicon/CAS-1438

CAS-1438: URL matching support for validation