better document Perl module requirements

[Ben Pfaff]

"patspam" in #pspp asked me why he needed to install the
libpspp-core-$VERSION.so library to use the Perl module when
perl-module/README says "Pspp is not required to use this module,
only to install it."  I'm proposing to push the following commit
that better explains what the Perl module requires.

Do you think that this is better?

Thanks,

Ben.

--8<--------------------------cut here-------------------------->8--

>From 3736fb716027e3e24d56359ebe2d292fcca30d07 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <address@hidden>
Date: Mon, 19 Apr 2010 20:30:32 -0700
Subject: [PATCH] perl-module: Better document Perl module requirements.

---
 perl-module/README |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/perl-module/README b/perl-module/README
index c8e9484..7c44cf3 100644
--- a/perl-module/README
+++ b/perl-module/README
@@ -7,8 +7,9 @@ system files.
 INSTALLATION
 
 To install you must have first installed and built pspp 0.7.2 or
-later.  Pspp is not required to use this module, only to install
-it. 
+later.  The Perl module does not use the installed PSPP binaries, but
+it does require the libpspp-core-$VERSION.so library installed with
+PSPP (see below).
 
 To install this module type the following:
 
@@ -34,7 +35,7 @@ required during installation, but are not needed to run the 
module.
 
 COPYRIGHT AND LICENCE
 
-Copyright (C) 2007, 2009 by Free Software Foundation
+Copyright (C) 2007, 2009, 2010 by Free Software Foundation
 
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License as
-- 
1.6.5


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 pour encourager les autres."
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