No restriction, limitation, or provision contained in any other law, either public or private, relating to the issuance of bonds, notes, or other obligations of a unit, or limiting the amount of taxes which may be levied in a unit, shall apply to bonds or notes issued under this chapter. The powers granted by this chapter are in addition to all other powers heretofore granted to a unit, and nothing herein contained shall be construed as prohibiting a unit from issuing bonds or notes under any public or private statute applicable to such unit. Nothing in this chapter shall be construed as mandatory for any unit to issue funding or refunding bonds under the terms and conditions of this chapter.