More flood protection

i created two plugins to add some protection against comment floods.

• flood protection by url
• flood protection by email

the code for both plugins come from the flood protection (by ip address) that is found in the wp-comments-post.php file, just ported to check the commenter’s email and url. i have kept them as separate plugins for better granular management.
one of the drawbacks of using either plugin is when multiple commenters leave the url or email field empty, so these plugins may not be ideal if you have a high traffic blog with active commenters.