Redefine ISC's int and boolean types to use <stdint.h> and <stdbool.h> types
This MR re#defines the isc_intNN_t and isc_uintNN_t types and related macros to C99 <stdint.h> types. Then it replaces ISC_PRINT_QUADFORMAT with PRI?64 format constants.
NOTE: Usage of PRI?nn format constants for the stdint types is a subject of future work.