Validation of checker settings

Hi,
Thanks for implementing my enhancements to weblinks checker listed in #472970: Enhancements to weblinks_checker. I have been going through the alterations you made, and I see that in weblinks_checker_settings_validate you changed some uses of $form to $form_state, for example you changed $form['weblinks_checker_limit']['#value'] to $form_state['#values'][weblinks_checker_limit']. However, I don't think this is quite right because $form_state['#values'] is empty whereas $form_state['values'] has everything we need, ie it does not need a # here.

Also when using $form_state['values'] the nested form elements are all moved to the top level, so
$form['weblinks_error_handling']['weblinks_checker_unpublish_after']['#value'] now becomes
$form_state['values']['weblinks_checker_unpublish_after'], with the middle bit removed.

I have attached a patch file _weblinks_checker.validate_settings.patch.txt for these corrections.

Jonathan