liabilities thereof and to provide the terms and conditions upon which the trustee or trustees or the holders of bonds or any proportion of them may enforce any covenant or rights securing or relating to the bonds; and (j) to exercise all or any part or combination of the powers herein granted; to make covenants, in addition to the covenants herein expressly authorized, of like or different character; to make such covenants and to do any and all such acts as may be necessary or desirable in order to secure its bonds or, in the absolute discretion of such authority, as will tend to make the bonds more marketable notwithstanding that such covenants or acts may not be enumerated herein. The validity of a pledge made by an authority pursuant to subdivision (a) of this section shall not be affected by the deposit of the funds pledged in a savings account in the name of the authority pursuant to the pledge agreement, and section 36a-291 shall not be applicable to such pledge.