CAS-1322: Improve Build System

First commit
CAS-1322: Improve Build System

Update the parent pom to ensure the notice.skip tag is valid
Merge pull request #339 from leleuj/CAS-1322

CAS-1322: Improve Build System
proper NOTICE files
[maven-release-plugin] prepare release v4.0.0-RC2
[maven-release-plugin] prepare for next development iteration
Removed unused import "Cas20ProtocolValidationSpecification"