README: work around a nasty behavior of gettext

[Akim Demaille]

commit 25347d885c73e34297f4d8d1bfaf3e5627068065
Author: Akim Demaille <address@hidden>
Date:   Sun Oct 7 10:06:46 2018 +0200

    README: work around a nasty behavior of gettext
    
    `make update-po` runs:
    
        package_gnu="$(PACKAGE_GNU)"; \
        test -n "$$package_gnu" || { \
          if { if (LC_ALL=C find --version) 2>/dev/null | grep GNU >/dev/null; 
then \
                 LC_ALL=C find -L $(top_srcdir) -maxdepth 1 -type f \
                               -size -10000000c -exec grep 'GNU @PACKAGE@' \
                               /dev/null '{}' ';' 2>/dev/null; \
               else \
                 LC_ALL=C grep 'GNU @PACKAGE@' $(top_srcdir)/* 2>/dev/null; \
               fi; \
             } | grep -v 'libtool:' >/dev/null; then \
             package_gnu=yes; \
           else \
             package_gnu=no; \
           fi; \
        }; \
    
    and based on the result, put GNU or not in the following line from
    bison.pot:
    
        # This file is distributed under the same license as the GNU bison 
package.
    
    It turns out that in my environment some log files had the 'GNU bison'
    string (note the lower case), but in distcheck, these files are no
    longer visible, so the generate bison.pot was different, and distcheck
    failed because we try to update bison.pot, which is read only in
    distcheck.
    
    The heuristics should look accept 'GNU Bison', not just 'GNU bison'.
    But let's please it to make sure we have our 'GNU'.
    
    * README: Mention 'GNU bison'.

diff --git a/README b/README
index 8689bab8..52ac0e1b 100644
--- a/README
+++ b/README
@@ -47,7 +47,7 @@ End:
 Copyright (C) 1992, 1998-1999, 2003-2005, 2008-2015, 2018 Free Software
 Foundation, Inc.
 
-This file is part of Bison, the GNU Compiler Compiler.
+This file is part of GNU bison, the GNU Compiler Compiler.
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by