Paragon Initiative Enterprises: Incomplete fix for #181225 (target=_blank vulnerability)

Hi, I believe the fix for 181225 is incomplete in the rules for Airship wysihtml parser rules. At https://github.com/paragonie/airship/blob/58f96aa0e5002b60e74456502d9bfc9483d77b3d/src/public/js/wysihtml5/parserrules/advancedandextended.js, the 'target' parameter for links is allowed to be...