Summary:
Have captcha libraries indicate what input to expect
Detailed Description:
Please add some sort of function like "getCaptchaInput()" to CaptchaLib. This
should allow all implementing classes to define what sort of form input they
expect. Now we are restricted to a <input type="text" /> field. But I would like
to have only <input type="hidden" /> fields! Also, someone might implement a
captch that works with radio buttons, or file uploads (for example by using
certificates).