Fix Launcher lag

Wallpaper manager seems to have issues with the NavBar activated
=> Render the wallpaper internally

Devices who want to use that needs to set:
<bool name="config_render_wallpaper_internally">true</bool>
in overlay/packages/apps/Launcher2/res/values/config.xml

Initial commit based on CM10.1 + changes for EOS4
Credits: nebkat
Thanks!

Change-Id: Id78b646ef6e75ee9cae305386508a73c1ae9eafd