JS/IE8: deliver legacy jQuery for IE8

This patch makes IcingaWeb deliver a legacy jQuery version for IE8
as it is no longer supported in jQuery 2.x. JS for IE8 will not be
delivered minified to ease troubleshooting on that buggy platform.

fixes #5866
refs #6417

application/layouts/scripts/layout.phtml

@@ -10,6 +10,8 @@ if (array_key_exists('_dev', $_GET)) {
   $cssfile = 'css/icinga.min.css';
 }
 
+$ie8jsfile  = 'js/icinga.ie8.js';
+
 $isIframe = isset($_GET['_render']) && $_GET['_render'] === 'iframe';
 $iframeClass = $isIframe ? ' iframe' : '';
 
@@ -47,7 +49,12 @@ $iframeClass = $isIframe ? ' iframe' : '';
 <div id="layout" class="default-layout">
 <?= $this->render('body.phtml') ?>
 </div>
+<!--[if IE 8]>
+<script type="text/javascript" src="<?= $this->href($ie8jsfile) ?>"></script>
+<![endif]-->
+<!--[if gt IE 8]><!-->
 <script type="text/javascript" src="<?= $this->href($jsfile) ?>"></script>
+<!--<![endif]-->
 <script type="text/javascript">
 var icinga = new Icinga({
   baseUrl: '<?= $this->href('/') ?>'

library/Icinga/Application/webrouter.php

@@ -47,6 +47,7 @@ $special = array(
     'css/icinga.css',
     'css/icinga.min.css',
     'js/icinga.dev.js',
+    'js/icinga.ie8.js',
     'js/icinga.min.js'
 );
 
@@ -72,6 +73,10 @@ if (in_array($path, $special)) {
             JavaScript::sendMinified();
             break;
 
+        case 'js/icinga.ie8.js':
+            JavaScript::sendForIe8();
+            break;
+
         default:
             return false;
     }

library/Icinga/Web/JavaScript.php

@@ -22,11 +22,15 @@ class JavaScript
     );
 
     protected static $vendorFiles = array(
-        // 'js/vendor/jquery-1.11.0',
         'js/vendor/jquery-2.1.0',
         'js/vendor/jquery.sparkline'
     );
 
+    protected static $ie8VendorFiles = array(
+        'js/vendor/jquery-1.11.0',
+        'js/vendor/jquery.sparkline'
+    );
+
     public static function listModuleFiles()
     {
         $list = array();
@@ -43,6 +47,12 @@ class JavaScript
         return self::send(true);
     }
 
+    public static function sendForIe8()
+    {
+        self::$vendorFiles = self::$ie8VendorFiles;
+        return self::send();
+    }
+
     public static function send($minified = false)
     {
         header('Content-Type: application/javascript');