It is the purpose of this chapter to vest in the county commission more efficient power and control over all public funds that may now or hereafter be under its management and control, to limit its power and authority to incur obligations and to approve and pay claims for current operating expenses in any fiscal year to the income of such year available for such purposes and to authorize the refunding of outstanding general obligations, other than bonded indebtedness, so that the provisions of this chapter may be put into effective operation.