Form submission handler for user_admin_settings().
function user_admin_settings_submit($form, &$form_state) {
config('user.settings')
->set('anonymous', $form_state['values']['anonymous'])
->set('admin_role', $form_state['values']['user_admin_role'])
->set('register', $form_state['values']['user_register'])
->set('verify_mail', $form_state['values']['user_email_verification'])
->set('signatures', $form_state['values']['user_signatures'])
->set('cancel_method', $form_state['values']['user_cancel_method'])
->set('notify.status_activated', $form_state['values']['user_mail_status_activated_notify'])
->set('notify.status_blocked', $form_state['values']['user_mail_status_blocked_notify'])
->set('notify.status_canceled', $form_state['values']['user_mail_status_canceled_notify'])
->save();
config('user.mail')
->set('cancel_confirm.body', $form_state['values']['user_mail_cancel_confirm_body'])
->set('cancel_confirm.subject', $form_state['values']['user_mail_cancel_confirm_subject'])
->set('password_reset.body', $form_state['values']['user_mail_password_reset_body'])
->set('password_reset.subject', $form_state['values']['user_mail_password_reset_subject'])
->set('register_admin_created.body', $form_state['values']['user_mail_register_admin_created_body'])
->set('register_admin_created.subject', $form_state['values']['user_mail_register_admin_created_subject'])
->set('register_no_approval_required.body', $form_state['values']['user_mail_register_no_approval_required_body'])
->set('register_no_approval_required.subject', $form_state['values']['user_mail_register_no_approval_required_subject'])
->set('register_pending_approval.body', $form_state['values']['user_mail_register_pending_approval_body'])
->set('register_pending_approval.subject', $form_state['values']['user_mail_register_pending_approval_subject'])
->set('status_activated.body', $form_state['values']['user_mail_status_activated_body'])
->set('status_activated.subject', $form_state['values']['user_mail_status_activated_subject'])
->set('status_blocked.body', $form_state['values']['user_mail_status_blocked_body'])
->set('status_blocked.subject', $form_state['values']['user_mail_status_blocked_subject'])
->set('status_canceled.body', $form_state['values']['user_mail_status_canceled_body'])
->set('status_canceled.subject', $form_state['values']['user_mail_status_canceled_subject'])
->save();
}