Live wallpaper improvements.

Now draws something a little nicer if the live wallpaper
doesn't have a preview.

Also: move Launcher2 back into "shared" so it has permission
to set the wallpaper.
diff --git a/Android.mk b/Android.mk
index e60613f..1bcd412 100644
--- a/Android.mk
+++ b/Android.mk
@@ -38,7 +38,7 @@
 
 LOCAL_PACKAGE_NAME := Launcher2
 LOCAL_CERTIFICATE := platform
-LOCAL_CERTIFICATE := shared
+# LOCAL_CERTIFICATE := shared
 
 LOCAL_OVERRIDES_PACKAGES := Launcher