Improved concurrency for trust store and validator.
Fix for VOMS-453
Merge branch 'feature/VOMS-453' into feature/concurrent
More tuning work.
Remove failing test (ref to local test certificate)
License headers
CertificateValidatorBuilder now follows builder pattern.
First attempt at a caching validator.
Leverage new validator builder where appropriate.
Fix for https://issues.infn.it/jira/browse/VOMS-455
More work on the Caching certificate validator.
Merge branch 'feature/concurrent' of github.com:italiangrid/voms-api-java into feature/concurrent

Conflicts:
	src/main/java/org/italiangrid/voms/util/CachingCertificateValidator.java