Use a grid view for bookmarks page.

The BrowserProvider now stores another blob
for a screenshot of the page.  If the current
page is a bookmark, store a screenshot.  When
viewing bookmarks, show a gridview of screenshots
of the bookmarks.

Requires a change to framework to add THUMBNAIL
to Browser.BookmarkColumns and to the HISTORY_PROJECTION
diff --git a/res/layout/bookmark_thumbnail.xml b/res/layout/bookmark_thumbnail.xml
new file mode 100644
index 0000000..439145a
--- /dev/null
+++ b/res/layout/bookmark_thumbnail.xml
@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2008 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:orientation="vertical"
+    android:padding="4dip"
+    android:background="@color/white">
+
+    <ImageView android:id="@+id/thumb"
+        android:src="@android:drawable/app_web_browser_sm"
+        android:scaleType="center"
+        android:layout_width="fill_parent"
+        android:layout_height="fill_parent" />
+
+    <TextView android:id="@+id/label"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom"
+        android:textAppearance="?android:attr/textAppearanceMedium"
+        android:textColor="@color/white"
+        android:maxLines="1"
+        android:paddingTop="3dip"
+        android:paddingBottom="3dip"
+        android:paddingLeft="2dip"
+        android:paddingRight="2dip"
+        android:scrollHorizontally="true"
+        android:background="#CC000000"/>
+</LinearLayout>