help2man: generate man pages for genltl and ltlfilt

* tools/help2man, tools/x-to-1.in: New files, copied from gnulib
1af55d85d9762a679b4302d5995f05ccd883e956.
* configure.ac: Create x-to-1 and export CROSS_COMPILING.
* Makefile.am: Distribute help2man.
* src/bin/Makefile.am (SUBDIRS): New.
* src/bin/man/Makefile.am: New file.
* src/bin/man/genltl.x, src/bin/man/ltlfilt.x: New files.
* src/bin/genltl.cc: Document the RANGE in the options,
and move the bibliography to genltl.x.
* README: Document src/bin/man

tools/x-to-1.in

@@ -0,0 +1,62 @@
+#! /bin/sh
+#
+# Copyright (C) 2001-2012 Free Software Foundation, Inc.
+#
+# 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
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# This program creates a program's manual from the .x skeleton and its --help
+# output.
+# The .x skeleton is a file containing manual page text that is not part of the
+# --help output. It is passed to help2man via its --include option. Its format
+# is described in the help2man documentation.
+
+update=
+while true; do
+  case "$1" in
+    --update) update=yes; shift;;
+    *) break;;
+  esac
+done
+
+if test $# != 5; then
+  echo "Usage: x-to-1 [OPTIONS] PERL HELP2MAN executable program.x program.1" 1>&2
+  exit 1
+fi
+PERL="$1"
+HELP2MAN="$2"
+executable="$3"
+aux="$4"
+output="$5"
+
+progname=`basename $aux .x`
+case "$PERL" in *"/missing perl") perlok=no;; *) perlok=yes;; esac
+if test @CROSS_COMPILING@ = no && test -f $executable && test $perlok = yes; then
+  echo "Updating man page $output"
+  echo "$HELP2MAN --include=$aux $executable > $output"
+  rm -f t-$progname.1
+  $HELP2MAN --include=$aux $executable > t-$progname.1 || exit 1
+  if test -n "$update"; then
+    # In --update mode, don't overwrite the output if nothing would change.
+    if cmp t-$progname.1 $output >/dev/null 2>&1; then
+      rm -f t-$progname.1
+    else
+      mv t-$progname.1 $output
+    fi
+  else
+    mv t-$progname.1 $output
+  fi
+else
+  echo "WARNING: The man page $output cannot be updated yet."
+fi