Nothing contained in this Act, or in any amendments made by this Act, shall be construed as - (1) asserting or conceding the constitutional powers or limitations of either the Congress or the President; (2) ratifying or approving any impoundment heretofore or hereafter executed or approved by the President or any other Federal officer or employee, except insofar as pursuant to statutory authorization then in effect; (3) affecting in any way the claims or defenses of any party to litigation concerning any impoundment; or (4) superseding any provision of law which requires the obligation of budget authority or the making of outlays thereunder.