Contracts and undertakings.

All contracts, agreements, obligations, and undertakings of such housing authorities heretofore entered into relating to financing or aiding in the development, construction, maintenance, or operation of any housing project or projects or to obtaining aid therefor from the United States Department of Housing and Urban Development, including, without limiting the generality of the foregoing, loan and annual contributions, contracts and leases with the United States Department of Housing and Urban Development, agreements with municipalities or other public bodies, including those which are pledged or authorized to be pledged for the protection of the holders of any notes or bonds issued by such housing authorities or which are otherwise made a part of the contract with such holders of notes or bonds, relating to cooperation and contributions in aid of housing projects, payments, if any, in lieu of taxes, furnishing of municipal services and facilities, and the elimination of unsafe and insanitary dwellings, and contracts for the construction of housing projects, together with all proceedings, acts, and things heretofore undertaken, performed, or done with reference thereto, are hereby validated, ratified, confirmed, approved, and declared legal in all respects, notwithstanding any defect or irregularity therein or any want of statutory authority.