HV-905 Providing a global config for auto unwrapping

An early attempt. Any thoughts on the direction?
> @Min(3) IntegerProperty myInt is also perfectly clear in its intention, but there is no type annotation. Should this also work out of the box?

It depends what you mean with working out of the box. In this case Validator will look for a `Min` constraint validator for a `IntegerProperty`. The instance itself will be validated. If the global unwrap validated value flag is set, it would check whether there is an un-wrapper for it, in which case it is applied. Intend is not based upon my knowledge of JavaFX types.

> What about @Min(3) IntegerProperty myInt then? This should work the same way out of the box (or not) as Optional<@Email String>.

It works different. See above. 

No, it works differently.