An Act amending the act of March 10, 1949 (P.L.30, No.14), known as the Public School Code of 1949, further providing for work to be done under contract let on bids and exception, for approved reimbursable rental for leases hereafter approved and approved reimbursable sinking fund charges on indebtedness and for approved reimbursable annual rental for leases of buildings and facilities for school use.