Redo reCAPTCHA validation API for K3.  I (heart) HMVC sub-requests.
Add Formo::add_before_submit() to add a field just before the submit button.
This is useful for tags, reCAPTCHA, etc.
Convert reCAPTCHA form API for K3 and Formo.  It works!
Turn back on "comment_add_form" events (none in core code anyway).