text: -- http://stackoverflow.com/questions/2568842/jquery-url-validator
  -- http://blog.mattheworiordan.com/post/13174566389/url-regular-expression-for-links-with-or-without
  CREATE OR REPLACE FUNCTION
      framework.check_url(url text)
      RETURNS bool AS $$
  BEGIN
      RETURN url ~* '((([A-Za-z]+:(?:\/\/)+)(?:[\-;:&=\+\$,\w]+@)?)(.)+)';
  END
  $$ LANGUAGE plpgsql;
  