Bug 13545 - Add barcode image generator service

If we add a script to Koha that can be passed a barcode, we will be able
to easily embed item and patron barcodes into html printable slips and
notices. This can be very helpful for librarians, as it means scanning
an image instead of typing in the barcode manually.

This patch adds a barcode image generator that can be passed a barcode
and an optional type ( defaults to Code39, all GD::Barcode types should
work ). This image can be embedded in html slips and notices.
( e.g. <img src="/cgi-bin/koha/svc/barcode?barcode=<<items.barcode>>"></img> )

Test Plan:
1) Apply this patch
2) Browse to /cgi-bin/koha/svc/barcode?barcode=123456789 on your server
3) Note the barcode image

Signed-off-by: Brandon <brandon_h27@hotmail.com>

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>

svc/barcode

@@ -0,0 +1,41 @@
+#!/usr/bin/perl
+
+# Copyright 2014 ByWater Solutions
+#
+# This file is part of Koha.
+#
+# Koha 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.
+#
+# Koha 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 Koha; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+use Modern::Perl;
+
+use CGI qw(header);
+use GD::Barcode;
+
+use C4::Auth qw(check_cookie_auth);
+
+my $input = new CGI;
+
+my ( $auth_status, $sessionID ) = check_cookie_auth( $input->cookie('CGISESSID'), { catalogue => '*' } );
+
+if ( $auth_status ne "ok" ) {
+    exit 0;
+}
+
+binmode(STDOUT);
+
+my $type = $input->param('type') || 'Code39';
+my $barcode = $input->param('barcode');
+
+print header('image/png');
+print GD::Barcode->new( $type, $barcode )->plot()->png();