More updates for Radiant comments

I'm slowly working on improving the commenting extension for Radiant.

The simple logic spam blocking has been working fine, and I've just updated it to ensure that the answers are not revealed in the HTML. Originally I just dropped the correct answer into a hidden field, but now the correct answer is hashed so that the value in the form is something like fc7272f83a6dbcfea6a3c81d3eb10e2e rather than the actual text.

Enjoy the more secure simple CAPTCHA system!

I've also added the ability to specify the number of comments per page on the admin side with Radiant::Config['comments.per\_page'] = 100. To any contributors, I am adding some features from the wild, but please write specs for your updates!

I hope to simplify the interface for managing comments as well, but that will come in time.


I've also sanitized the content_html so that you're no longer vulnerable to inserted script elements.