Contact module email spoofing

When a person used the contact form their email address is used as the "from" address for the resulting email. Unless the visitor's email address is handled by the drupal server's email server, then many spam filters will see this as an email spoof.

I propose modifying contact_mail_page_submit(509):
$from = variable_get('site_mail', '');
$headers = array('Reply-To' => $form_values['mail']);

And contact_mail_user_submit(375):
$from = variable_get('site_mail', '');
$headers = array('Reply-To' => $user->mail);

After those changes are made, just adding the $headers variable to the end of the 4 drupal_mail calls in the before mentioned functions will solve the problem.

This implementation allows the person who receives the contact email will be able to reply to it normally and the email's likelihood of reaching the site contact person is increased.