[WIP] Multi-window

This is a big work in progress, which currently has some bugs,
but begins to look okay.

You can already multitask a little bit, by using the
app switcher and long-pressing an icon, then select "Add to
Split View".
Last window touched gets the key focus.

Code is very ugly, I know. Don't merge it, don't use it
for now. Unless you want to make your code ugly.

Enjoy :)

Change-Id: I4a03a84539fd3ac1273f0d3503fe8fafcd16be26
add bools to overlay for Samsung CDMA SMS decoding hacks

ported from CM7/9/10

required by :

Change-Id: I28093cdb8770f98b94cedbff63e6121c798cf9af