Add CHANGES entry

5007.   [cleanup]       Replace custom ISC boolean and integer data types
                        with C99 stdint.h and stdbool.h types. [GL #9]

CHANGES

+5007.	[cleanup]	Replace custom ISC boolean and integer data types
+			with C99 stdint.h and stdbool.h types. [GL #9]
+
 5006.	[cleanup]	Code preparing a delegation response was extracted from
 			query_delegation() and query_zone_delegation() into a
 			separate function in order to decrease code