Updated documents UX around action bar.

Change action bar to match current design; drawer is always available
and navigation dropdown is used to interact with current traversal
path in hierarchy.  On first launch, show recents with drawer
expanded.  On subsequent launches, resume from last location with
drawer closed.  If last location root isn't applicable, then behave
like initial launch.  Move sort order into action bar submenu.

Delete documents using contract.  Use unstable provider when
inflating DocumentInfo from Uri.

Bug: 10330219, 10510851
Change-Id: I6e94637d70ebca156a6c5d50272e878156d0dd62
diff --git a/res/menu/activity.xml b/res/menu/activity.xml
index 575336c..e182159 100644
--- a/res/menu/activity.xml
+++ b/res/menu/activity.xml
@@ -28,6 +28,23 @@
         android:actionViewClass="android.widget.SearchView"
         android:imeOptions="actionSearch" />
     <item
+        android:id="@+id/menu_sort"
+        android:title="@string/menu_sort"
+        android:icon="@drawable/ic_menu_sort"
+        android:showAsAction="always">
+        <menu>
+            <item
+                android:id="@+id/menu_sort_name"
+                android:title="@string/sort_name" />
+            <item
+                android:id="@+id/menu_sort_date"
+                android:title="@string/sort_date" />
+            <item
+                android:id="@+id/menu_sort_size"
+                android:title="@string/sort_size" />
+        </menu>
+    </item>
+    <item
         android:id="@+id/menu_grid"
         android:title="@string/menu_grid"
         android:icon="@drawable/ic_menu_grid"