Log Message:
Update to GNU Prolog version 1.3.1.

Changes in GNU Prolog version 1.3.1:

* add working sigaction detection to detect fault addr (e.g. Mac OS X)
* add gplc option --no-mult-warn
* add prolog flags suspicious_warning, multifile_warning
* detect integer underflow/overflow in the parser
* fix a memory leak in catch/3
* increase limits (MAX_VAR_NAME_LENGTH=1024 and MAX_VAR_IN_TERM=10240)
* add PL_INT_LOWEST_VALUE and PL_INT_GREATEST_VALUE to gprolog.h
* prefix all global symbols, constants and types with Pl_ PL_ Pl
* fix a bug in the byte-code due to new max number of atoms
* provide a minimal gprolog.h
* detect if struct sigcontext needs asm/sigcontext.h on linux
* modify gplc: --c-compiler also sets linker and --linker added
* port to x86_64/bsd - many thanks to:
  David Holland <dholland@netbsd.org>
* fix problem using ebx as global reg (bug in gcc 4.3.2)
* fix a bug in is/2 with [X] (X should only be an integer)
* fix a bug with atoms '/*' '*/' and '%' (were not quoted)
* increase maximum number of atoms to 1048576 (2^20)
* increase default stack sizes (16Mb for heap, 8Mb for others)
* fix stack alignment for x86_64/Solaris
* include patch from Paul Eggert <eggert@cs.ucla.edu> for sparc/solaris8
* port to x86_64/Solaris - many thanks to:
  Scott L. Burson <Scott@coral8.com>
* fix a bug in arithmetics (mod)
* fix a bug in the FD solver (under 64 bits machines)