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?
it was directly added by your changes, but the version on 4.3 did not have an equals at all. I thought it would not harm. On the other hand `hashCode` is missing, so I probably just get rid of it altogether.