Add changed? macro

[NoahTheDuke]

As discussed on slack.

Includes a wrapper around play-dynamic-ability.

[butzopower]

This looks great, testing it in the wild I think the expected is maybe reported incorrectly in test report.

I set it up to fail checking for change of +3 (when implementation is +2):

(is (changed? [(count (:hand (get-corp))) 3]
                  (click-prompt state :corp "Yes"))
        "Draw 1 (plus mandatory)")

and it gave me the following:

Draw 1 (plus mandatory)
(count (:hand (get-corp))) => (0 to 2)
Expected :-3
Actual   :2

[NoahTheDuke]

Ah crap, thanks for double checking that. I thought I had it right. 😭