clarify the hidden APIs in reference with better tooltips

Change-Id: Iaa843b4a0462195084fb7a35e826eeec92d50c64
diff --git a/tools/droiddoc/templates-sdk/assets/js/docs.js b/tools/droiddoc/templates-sdk/assets/js/docs.js
index 8c00da7..1996dac 100644
--- a/tools/droiddoc/templates-sdk/assets/js/docs.js
+++ b/tools/droiddoc/templates-sdk/assets/js/docs.js
@@ -2382,7 +2382,8 @@
     // Grey things out that aren't available and give a tooltip title
     if (apiLevelNum > selectedLevelNum) {
       obj.addClass("absent").attr("title","Requires API Level \""
-            + apiLevel + "\" or higher");
+            + apiLevel + "\" or higher. To reveal, change the target API level "
+              + "above the left navigation.");
     }
     else obj.removeClass("absent").removeAttr("title");
   });
diff --git a/tools/droiddoc/templates-sdk/customizations.cs b/tools/droiddoc/templates-sdk/customizations.cs
index 985f059..d54d371 100644
--- a/tools/droiddoc/templates-sdk/customizations.cs
+++ b/tools/droiddoc/templates-sdk/customizations.cs
@@ -214,7 +214,8 @@
 <a class="totop" href="#top" data-g-event="left-nav-top">to top</a>
       <div id="api-nav-header">
         <div id="api-level-toggle">
-          <label for="apiLevelCheckbox" class="disabled">API level: </label>
+          <label for="apiLevelCheckbox" class="disabled"
+            title="Select your target API level to dim unavailable APIs">API level: </label>
           <div class="select-wrapper">
             <select id="apiLevelSelector">
               <!-- option elements added by buildApiLevelSelector() -->
@@ -239,7 +240,7 @@
             <div id="packages-nav" class="scroll-pane">
 
               <ul>
-              	<?cs call:package_link_list(docs.packages) ?>
+                <?cs call:package_link_list(docs.packages) ?>
               </ul><br/>
 
             </div> <!-- end packages-nav -->