+ add --with-lib-prefix option to allow configuring for old/new flavors
of OS/2 EMX.
+ modify check for gnat version to allow for year, as used in FreeBSD
port.
+ modify check_existence() in db_iterator.c to simply check if the
path is a directory or file, according to the need. Checking for
directory size also gives no usable result with OS/2 (cf: 20120107).
+ support OS/2 kLIBC (patch by KO Myung-Han).