Improve mouseover and titles on goto, related to elixir-lang#968

Author: José Valim

assets/js/templates/sidebar-items.handlebars

@@ -19,7 +19,7 @@
           {{node.title}}
         {{/if}}
 
-        <span class="icon-goto" title="Go to"></span>
+        <span class="icon-goto" title="Go to {{node.title}}"></span>
       </a>
 
       <ul>
@@ -43,7 +43,7 @@
             <li class="docs">
               <a href="{{node.id}}.html#{{group.key}}" class="expand">
                 {{group.name}}
-                <span class="icon-goto" title="Go to"></span>
+                <span class="icon-goto" title="Go to {{group.name}}"></span>
               </a>
               <ul class="{{group.key}}-list deflist">
                 {{#each group.nodes}}

assets/less/sidebar.less

@@ -173,6 +173,7 @@
       }
 
       a.expand span {
+        color: @lightestGray;
         visibility: hidden;
         padding: 0 8px 0 2px;
         font-size: 0.8em;
@@ -181,6 +182,10 @@
       a.expand:hover span {
         visibility: visible;
       }
+
+      a.expand span:hover {
+        color: @white;
+      }
     }
 
     &>li {