All bonds and all temporary notes issued under the provisions of this chapter [this article] and the debts evidenced thereby shall be obligatory on the Town of Middletown in the same manner and to the same extent as other debts lawfully contracted by it but no pledge of any special funds to their payment is intended by this chapter. The bonds and notes issued hereunder shall be excepted from the operation of section 45-12-2 of the General Laws, as amended. No such obligation shall at any time be included in the debt of said town for the purpose of ascertaining its borrowing capacity. The town shall annually appropriate a sum sufficient to pay the interest upon bonds and also to pay the principal of any bonds maturing in such year, until said bonds and the interest thereon are paid in full. (P.L. 1958, ch. 138, § 1.)