4.3.2.final patch

For 4.3.2 I only applied the HV-912 changes. I did not move `ConstraintMapping` as on master (part of the "reducing accessibility of some classes and methhods". I think it is technically not necessary and it could break existing clients. @gunnarmorling, wdyt?
The method should not be set accessible here, only the copy hold in `ValidatorImpl`.