No follow Custom Text widget or Disable?

I am having Problems with the custom Text widget it seem a great loophole for Massive outgoing One Way linking

“stop thief!”

Any How is there any way of removing the Functions

function wp_widget_text

function wp_widget_text_control

function wp_widget_text_register

from wp-includes/widget.php so its not available from the Themes

Or

Nofollow Tag on the text-links going into the Custom Text Box

Any Ideas

willing to Learn