Split configuration constants into local XConfigUtils classes instead of piling them up in AnnotationConfigUtils
AbstractTypeHierarchyTraversingFilter leniently ignores non-loadable super classes and interfaces

Issue: SPR-12042
Polishing
Latest dependency updates (Groovy 2.3.5, Hibernate Validator 4.3.2 & 5.1.2, Jetty 9.2.2)