Changed the tree cell value label in the .xul file and added the .setAttribute property in the .js file to fix bug #20639. r=sgehani

xpinstall/res/content/institems.js

@@ -37,13 +37,11 @@ function addTreeItem(num, modName, url)
   newrow.setAttribute("rowName", modName);
 
   var elem = document.createElement('treecell');
-  var text = document.createTextNode(modName);
-  elem.appendChild(text);
+  elem.setAttribute("value", modName);
   newrow.appendChild(elem);
 
   var elem = document.createElement('treecell');
-  var text = document.createTextNode(url);
-  elem.appendChild(text);
+  elem.setAttribute("value", url);
   newrow.appendChild(elem);
 
   newitem.appendChild(newrow);

xpinstall/res/content/institems.xul

@@ -46,8 +46,8 @@
 
 			        <treehead>
 			            <treerow>
-			                <treecell>&moduleName.label;</treecell>
-			                <treecell>&moduleSource.label;</treecell>
+			                <treecell value="&moduleName.label;" />
+			                <treecell value="&moduleSource.label;"/>
 			            </treerow>
 			        </treehead>