Recents: Implement CardStackView Redesign

Summary:
- WIP

TODO:
- Implment a bitmap cache for card previews.
- Crop floating window thumbnails: handle landscape
  and move to WindowManagerService.java.
- (...)

Key Contibutors:
- Oliver @oreiche
- Yamil @beerbong
- Carlo @BigBrother1984
- Evan @linuxman94
- Aaron @aaronpoweruser
- Arz @arzbhatia
- Lo Huot

PS6: Add new overrided methods from swipe helper

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I47a021df1e0931d774c7db9039ebfba66a41aaa5
Merge pull request #4 from atomicspaceindian/kitkat

Recents: Implement CardStackView Redesign