Option to add "Terms of Use" to User Login form

Some sites require that you agree to the Terms of Use each time that you login. I've create a patch that add this option to the Terms of Use settings page.

To accomplish this, moved the TOU form generation logic to a separate function (terms_of_use_generate_form), which can be called by both terms_of_use_form_user_register_form_alter and terms_of_use_form_user_login_alter.