perl5.000 patch.0m: [various fixes, hint file updates and documentation]

perl5.000 patch.0m: [various fixes, hint file updates and documentation]

This is my patch  patch.0m  for perl5.000.
This patch fixes all remaining problems that I am aware of, and for
which I have a solution.  It also updates some hint files and
documentation.

Here's what's new:

Configure
        Protect against spaces in uname -m output (unicos).
        Look in <stdlib.h> for malloctype and freetype.
        Check if user has void free() or int free().
        Look in linux/signal.h for signal names.

MANIFEST
MANIFEST.new
        Two new hint files:  cxux.sh and PowerUNIX.sh.
        Sorted.

README
        Indicate what gets installed and where it usually goes.
    Thanks to Hallvard B. Furuseth <h.b.furuseth@usit.uio.no>
    for suggesting this.

U/Myinit.U
        Update extliblist comment.

U/dist3_051.pat
    This file contains patches to dist 3 (PL 51) that I used to generate
    Configure for perl.

U/mallocsrc.U
        Look in <stdlib.h> for malloctype and freetype.
        Check if user has void free() or int free().

config_h.SH
config.H
        Add Free_t to handle void free() vs. int free().

ext/DynaLoader/README
        Updated comment.

ext/POSIX/POSIX.pm
        creat() has 2 arguments, not 3 (thanks, Paul).

ext/POSIX/POSIX.xs
        Fix return type of lseek.

ext/SDBM_File/sdbm/sdbm.h
        Add I_STDLIB guard on #include <stdlib.h>

ext/util/extliblist
        Add note indicating this is obsolete.  Don't remove it because
    people might be using it for their own private extensions.

hints/PowerUNIX.sh
hints/cxux.sh
        New files.  Written by Tom.Horsley@mail.hcsc.com

hints/linux.sh
        Simplified.

lib/ExtUtils/MakeMaker.pm
        Typo fixed, only affected aix?

malloc.c
        Allow for possible int free().

perl.h
pp_sys.c
util.c
        If the user is not using vfork, move the #define vfork fork
    util after various #include files.  Since vfork() and fork() might
    have different prototypes, the #define could cause a conflict in
    system header files.  (Reported for 386bsd.)

Makefile.SH
        make realclean will remove h2xs and makeaperl (but leave behind
        the .SH versions, of course).