Key item lists to maintain identity across redraws

Fixes #667. This issue was due to the fact that Mithril would change the "Lock" badge into a "Sticky" badge, but the tooltip initialization would not be triggered because it was using the same element. By maintaining element identity, the "Lock" badge will remain untouched, and a new element for the "Sticky" badge will be inserted before it. See https://lhorie.github.io/mithril/mithril.html#dealing-with-focus for more information.

js/lib/helpers/listItems.js

@@ -41,7 +41,8 @@ export default function listItems(items) {
             (item.itemName ? 'item-' + item.itemName : ''),
             className,
             (active ? 'active' : '')
-          ])}>
+          ])}
+            key={item.itemName}>
             {item}
           </li>,
       ' '