UP-4192 CVE-2014-5059 block security vulnerability.

Fixes out of the box `security.properties` configuration.
Adds warning to `security.properties` documenting the configuration trap.
UP-4192 CVE-2014-5059 guarantee CAS security context successfully sets principal ID.

Detects and throws in case where principal UID setting is blocked.
License header formatting per mvn:license.