Add some cleaner looking images for previews and switch to using nine patch images for background so no landscape specific images are needed.

Patch Set 2:
  Include larger home and delete buttons for sw600dp-mdpi and adjust the preview height for landscape on sw600dp devices.

Change-Id: I8e0fed5693717cb1eec538f486e108e8fd988c2e
Avoid NPE when calling info.toString()
Revert default value for title in ItemInfo.
Allow stretch screens setting to stretch the home screen fully instead of some padding remaining and not offering too much of a difference.
Nexus 4 wallpaper

Signed-off-by: iceandfire <arhamjamal@gmail.com>