A bondholder or trustee for a bondholder shall have the right in addition to all other rights which may be conferred on such bondholder or trustee, subject only to any contractual restrictions binding upon such bondholder or trustee:
     (a) By mandamus, injunction or other civil action to compel said Authority and the commissioners, officers, agents or employees thereof to perform each and every term, provision and covenant contained in any contract of said authority with or for the benefit of such bondholder or trustee, and to require the carrying out of any or all such covenants and agreements of said Authority and the fulfillment of all duties imposed upon said Authority by this Act.
     (b) By civil action to enjoin any acts or things which may be unlawful, or the violation of any of the rights of such bondholders.