isc_mktcpaddress.  All callers updated.  The logic for
	checking the return value from gethostbyname2() was inverted.
(isc_mktcpaddress): New function.
(isc_addresssize): New function.
(isc_addressfamily): New function.
(isc_addresspointer): New function.
(isc_bindtcp): Use isc_addresspointer() and isc_addresssize() to
	simplify the code.