arm_compute v18.11
diff --git a/documentation/navtree.js b/documentation/navtree.js
index 9df45a7..e6d31b0 100644
--- a/documentation/navtree.js
+++ b/documentation/navtree.js
@@ -1,4 +1,6 @@
 var navTreeSubIndices = new Array();
+var arrowDown = '▼';
+var arrowRight = '►';
 
 function getData(varName)
 {
@@ -71,17 +73,17 @@
 
 function getScript(scriptName,func,show)
 {
-  var head = document.getElementsByTagName("head")[0]; 
+  var head = document.getElementsByTagName("head")[0];
   var script = document.createElement('script');
   script.id = scriptName;
   script.type = 'text/javascript';
-  script.onload = func; 
-  script.src = scriptName+'.js'; 
-  if ($.browser.msie && $.browser.version<=8) { 
+  script.onload = func;
+  script.src = scriptName+'.js';
+  if ($.browser.msie && $.browser.version<=8) {
     // script.onload does not work with older versions of IE
     script.onreadystatechange = function() {
-      if (script.readyState=='complete' || script.readyState=='loaded') { 
-        func(); if (show) showRoot(); 
+      if (script.readyState=='complete' || script.readyState=='loaded') {
+        func(); if (show) showRoot();
       }
     }
   }
@@ -94,18 +96,17 @@
   var n = node;
   while (n.parentNode) { level++; n=n.parentNode; }
   if (node.childrenData) {
-    var imgNode = document.createElement("img");
+    var imgNode = document.createElement("span");
+    imgNode.className = 'arrow';
     imgNode.style.paddingLeft=(16*level).toString()+'px';
-    imgNode.width  = 16;
-    imgNode.height = 22;
-    imgNode.border = 0;
+    imgNode.innerHTML=arrowRight;
     node.plus_img = imgNode;
     node.expandToggle = document.createElement("a");
     node.expandToggle.href = "javascript:void(0)";
     node.expandToggle.onclick = function() {
       if (node.expanded) {
         $(node.getChildrenUL()).slideUp("fast");
-        node.plus_img.src = node.relpath+"arrowright.png";
+        node.plus_img.innerHTML=arrowRight;
         node.expanded = false;
       } else {
         expandNode(o, node, false, false);
@@ -113,15 +114,13 @@
     }
     node.expandToggle.appendChild(imgNode);
     domNode.appendChild(node.expandToggle);
-    imgNode.src = node.relpath+"arrowright.png";
   } else {
     var span = document.createElement("span");
-    span.style.display = 'inline-block';
+    span.className = 'arrow';
     span.style.width   = 16*(level+1)+'px';
-    span.style.height  = '22px';
     span.innerHTML = '&#160;';
     domNode.appendChild(span);
-  } 
+  }
 }
 
 var animationInProgress = false;
@@ -195,7 +194,7 @@
       var aname = '#'+link.split('#')[1];
       var srcPage = stripPath(pathName());
       var targetPage = stripPath(link.split('#')[0]);
-      a.href = srcPage!=targetPage ? url : "javascript:void(0)"; 
+      a.href = srcPage!=targetPage ? url : "javascript:void(0)";
       a.onclick = function(){
         storeLink(link);
         if (!$(a).parent().parent().hasClass('selected'))
@@ -213,7 +212,7 @@
       a.onclick = function() { storeLink(link); }
     }
   } else {
-    if (childrenData != null) 
+    if (childrenData != null)
     {
       a.className = "nolink";
       a.href = "javascript:void(0)";
@@ -262,17 +261,13 @@
     } else {
       if (!node.childrenVisited) {
         getNode(o, node);
-      } if (imm || ($.browser.msie && $.browser.version>8)) { 
+      } if (imm || ($.browser.msie && $.browser.version>8)) {
         // somehow slideDown jumps to the start of tree for IE9 :-(
         $(node.getChildrenUL()).show();
       } else {
         $(node.getChildrenUL()).slideDown("fast");
       }
-      if (node.isLast) {
-        node.plus_img.src = node.relpath+"arrowdown.png";
-      } else {
-        node.plus_img.src = node.relpath+"arrowdown.png";
-      }
+      node.plus_img.innerHTML = arrowDown;
       node.expanded = true;
     }
   }
@@ -341,7 +336,7 @@
         getNode(o, node);
       }
       $(node.getChildrenUL()).css({'display':'block'});
-      node.plus_img.src = node.relpath+"arrowdown.png";
+      node.plus_img.innerHTML = arrowDown;
       node.expanded = true;
       var n = node.children[o.breadcrumbs[index]];
       if (index+1<o.breadcrumbs.length) {
@@ -478,10 +473,9 @@
   o.node.relpath = relpath;
   o.node.expanded = false;
   o.node.isLast = true;
-  o.node.plus_img = document.createElement("img");
-  o.node.plus_img.src = relpath+"arrowright.png";
-  o.node.plus_img.width = 16;
-  o.node.plus_img.height = 22;
+  o.node.plus_img = document.createElement("span");
+  o.node.plus_img.className = 'arrow';
+  o.node.plus_img.innerHTML = arrowRight;
 
   if (localStorageSupported()) {
     var navSync = $('#nav-sync');