change name of offline doc tab to "API reference"

and put the version number in the secondary nav bar (it was there anyway).

Change-Id: I4b49581eca6afa445a434cd6ae31572d01f276ef
(cherry picked from commit 06bdd78284)

tools/droiddoc/templates-sdk-refonly/components/masthead.cs

@@ -138,7 +138,12 @@
       <li class="dac-nav-item develop">
         <a class="dac-nav-link has-subnav" href="/reference/packages.html" zh-tw-lang="參考資源" 
         zh-cn-lang="参考" ru-lang="Справочник" ko-lang="참조문서" ja-lang="リファレンス" 
-        es-lang="Referencia">Android <?cs var:sdk.version ?>&nbsp;r<?cs var:sdk.rel.id ?></a>
+        es-lang="Referencia">API Reference</a>
+      <div class="dac-nav-secondary develop">
+        <h1 style="font-size: 20px; line-height: 24px; margin: 20px; color:#444"
+          >Android <?cs var:sdk.version ?> r<?cs var:sdk.rel.id ?>
+        </h1>
+      </div>
       </li>
     </ul>
   </nav>