DATAJPA-307 - Removed null checks as we expect engine to be never null.
DATAJPA-307 - Extended SoftDelete implementation to support QueryDslPredicateExecutor repositories.

TODO:
 - Native Query in JPASoftDeleteQueryAugmentor
 - Native Query support in QueryDslSoftDeleteQueryAugmentor
 - QueryAugumentationEngineAware implementation in QueryDslRepositorySupport
 - Review PropertyChangeEnsuringBeanWrapper
 - More tests