Documentation: add gitman.info target

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/cat-texi.perl

@@ -0,0 +1,38 @@
+#!/usr/bin/perl -w
+
+my @menu = ();
+my $output = $ARGV[0];
+
+open TMP, '>', "$output.tmp";
+
+while (<STDIN>) {
+	next if (/^\\input texinfo/../\@node Top/);
+	next if (/^\@bye/ || /^\.ft/);
+	if (s/^\@top (.*)/\@node $1,,,Top/) {
+		push @menu, $1;
+	}
+	s/\(\@pxref{\[URLS\]}\)//;
+	print TMP;
+}
+close TMP;
+
+printf '\input texinfo
+@setfilename gitman.info
+@documentencoding us-ascii
+@node Top,,%s
+@top Git Manual Pages
+@documentlanguage en
+@menu
+', $menu[0];
+
+for (@menu) {
+	print "* ${_}::\n";
+}
+print "\@end menu\n";
+open TMP, '<', "$output.tmp";
+while (<TMP>) {
+	print;
+}
+close TMP;
+print "\@bye\n";
+unlink "$output.tmp";