First cut at new home screen customization for xlarge displays.

- Add new layout for xlarge, removing hotseat, next/prev page, etc.
- Add a "+" button in top right which switches to customization mode
- Add a widget chooser which slides up from bottom of screen
- Initial support for dragging widgets onto home screen

Change-Id: I14e2e013ccceff4066fcb7c4492b4f6bef6595e7

src/com/android/launcher2/LauncherAppWidgetInfo.java

@@ -17,6 +17,7 @@
 package com.android.launcher2;
 
 import android.appwidget.AppWidgetHostView;
+import android.content.ComponentName;
 import android.content.ContentValues;
 
 /**
@@ -29,6 +30,7 @@ class LauncherAppWidgetInfo extends ItemInfo {
      * {@link android.appwidget.AppWidgetManager} for updates.
      */
     int appWidgetId;
+    ComponentName providerName;
     
     /**
      * View that holds this widget after it's been created.  This view isn't created