Provide a feedback button in the interface

Meant to resolve #1653. As per @dwhly's suggestion the dropdown menu is now accessible even when not logged in. Note: items relevant to only logged in users are not shown.

h/static/styles/topbar.scss

@@ -55,7 +55,7 @@ body {
       font-family: $sans-font-family;
     }
 
-    & > * {
+    & > *:first-child, & > *:last-child {
       line-height: 28px;
       margin: 0 .72em;
     }