new syntax for RequiredValidUntil filter

[Tom Scavo]

On Tue, Feb 14, 2017 at 9:28 AM, Rod Widdowson <rdw at steadingsoftware.com> wrote:
>> Why not REQUIRE @maxValidity instead?
>
> We cannot, that would break backwards compatibility.  It might be compatibility against broken behaviour but we still cannot break
> configurations (I maintain). At least in 3.4 you'll get a warning for that sort of non-sense.
>
>> but it makes no sense.
> None at all, I agree.  It's been a thorn in my side since V2 days

Then why not start over and introduce a brand new filter:
RequiredValidUntilThatMakesSense

(I'm kidding about the filter name but the rest is a real suggestion)

As you know, checking validUntil is an essential part of the metadata
security model. We shouldn't dance around security for historical
reasons.

Tom