Since we already have the define ISC_STATUS_LENGTH for the the length of
the status vector, we should use it! Replaced 'status[20]' with
'status[ISC_STATUS_LENGTH]'.
Replaced the different symbolic names for the maximum length of a path
(MAX_PATH, MAX_PATH_LENGTH, MAXPATHLEN) with one uniq symbol MAXPATHLEN.
o since the define 'VAX' was only used to tell that the byte order is
LITTLE_ENDIAN (it have nothing else to do with the VAX computer family)
it can safely replaced with '!WORDS_BIGENDIAN'.
o check if pointers are 64 bit
o replaced HAS_64BIT_POINTERS with 'SIZEOF_VOID_P == 8'
