HV-905 Providing a global config for auto unwrapping

An early attempt. Any thoughts on the direction?
> Wow, the discussion got very deep :)

Hehe, yes. A heated debate every now and then keeps up the spirit :)

>  I feel that an average user will certainly get confused by implicit unwrapping, global unwrapping, and annotation unwrapping.

Yes, that's true. Hence the desire to find simple, consistent and comprehensible rules. Otherwise users will dislike it.

> Keep it stupid simple, which for me translate to: @UnwrapValidatedValue present ? unwrap, else, do not unwrap.

That's for sure an option if we don't find any better way. It works and there is no ambiguity. But consider it's a) quite specific cases we're discussing (still we need to address them of course) and b) think of the poor JavaFX user who works with dozens of *Property attributes and needs to add `@UnwrapValidatedValue` all the time. This adds up over time.