HV-920 Adding a regular expression based URL constraint validator which ...

...needs to be configured via XML or via a ConstraintDefinitionContributor
Sure. `@URL` makes use of constraint composition in this case. The intention of the regexp is to further narrow down the valid URL, eg *.html or something. It is not supposed to be a general URL matching regexp. We had a quite long discussion once we added this regexp parameter. You might have been involved!?