Nothing contained in this chapter shall be deemed to supplant or modify the provisions of any special or private act relating to the zoning or zoning powers of any municipality or county to which the special or private act is applicable, and all the provisions of the special or private act shall remain in full force and effect; but, insofar as this chapter is not inconsistent with the provisions of such special or private act, this chapter shall apply to the zoning powers and procedure of the municipality or county.