implement api level toggling
 and rename navtree.js to android-developer-reference.js for all reference related scripts
 TODO: shading for hidden classes in the treeview navigation... these aren't dynamic yet.
diff --git a/tools/droiddoc/templates/packages.cs b/tools/droiddoc/templates/packages.cs
index a358dca..c2d8c75 100644
--- a/tools/droiddoc/templates/packages.cs
+++ b/tools/droiddoc/templates/packages.cs
@@ -20,7 +20,7 @@
 <?cs set:count = #1 ?>
 <table class="jd-sumtable">
 <?cs each:pkg = docs.packages ?>
-    <tr <?cs if:count % #2 ?>class="alt-color"<?cs /if ?> >
+    <tr class="<?cs if:count % #2 ?>alt-color<?cs /if ?> api apilevel-<?cs var:pkg.since ?>" >
         <td class="jd-linkcol"><?cs call:package_link(pkg) ?></td>
         <td class="jd-descrcol" width="100%"><?cs call:tag_list(pkg.shortDescr) ?>&nbsp;</td>
     </tr>