This Article shall be deemed to provide an additional and alternative method for the doing of the things authorized hereby and shall be regarded as supplemental and additional to powers conferred by other laws, and shall not be regarded as in derogation of or as repealing any powers now existing under any other law, either general, special or local; provided, however, that the issuance of revenue bonds or revenue refunding bonds under the provisions of this Article need not comply with the requirements of any other law applicable to the issuance of bonds. (1957, c. 1131, s. 10.)