[Validator] Fix constraint violation message parameterization
[Validator] Fixed value-to-string conversion in constraint violations
[Validator] Simplified IBAN validation algorithm
[Validator] Fixed and simplified IsbnValidator
[Validator] Simplified IssnValidator
[Validator] Simplified and explained the LuhnValidator
[Validator] Added "{{ value }}" parameters where they were missing
[Validator] Fixed date-to-string conversion tests to match ICU 51
[Validator] Fixed CS
[Validator] Renamed valueToString() to formatValue(); added missing formatValue() calls
properly handle null data when denormalizing

If null is passed to denormalize(), no property values can be set on
the denormalized object. Additionally, this fixes passing values to
the denormalized object's constructor if the incoming data is an object.
[Validator] Constraint validators now use the 2.5 API. For incompatible validators, legacy validators were created
[Validator] Added extensive test coverage for the constraint validators for the different APIs
[FrameworkBundle] Made ConstraintValidatorFactory aware of the legacy validators
[Validator] CS fixes
[Validator] Fixed failing tests
fixed CS
partially reverted previous commit
[Validator] Removed information from the violation output if the value is an array, object or resource

This was decided in the discussion of #10687.
[Validator] Added more detailed inline documentation