Frameworks: Slim recent app screen
One of the parts on AOSP google missed to update/improve in the last
couple of releases is the recent app screen to allow better and faster
multitasking. I had always a special vision how it could/should look
and gives the user a faster workflow.

This commit is now our new recent screen. It is a complete new implementation
and replaces googles AOSP recent app screen. The code changes in the base itself
are quiet miniml to call the new recent screen.

Some notes:

1. This patch needs a new repo: frameworks_opt_cards which is a central repo
   to get any kind of googles cards style. Thanks Gabrielle Mariotti a ton who
   made the base for this library and hellped a lot out.  We just fixed together with him some parts
   and mad it useable as AOSP central library. So we can use it later for other
   changes as well

2. Preload needs to work 100%. So it is needed to check that the calling parts
   (like hw key rebinding, pie, navigation bar) do a proper preload. If they do not
   recent screen will just not show up. To follow what they are doing you can enable
   debug in RecentController.java which exactly shows what was called.

Some notes to the patch itself:

- Recent app  screen slides from the right edge into the screen

- Show recent apps in new google card style. Most recent apps show
  expanded with the app screenshot. Other are collapsed. Of course
  the user can change expanded/collapse of each app during the session where the state
  will be restored on next access.

- Compared to AOSP recents we do a 3 stage loading
  1. step: preload the task list and build or update the cards (does not load any content at this point)
  2. step: User actually toggled the recent screen....icons, text and screenshot thumbnail which will get visible are loaded now
  3. step: Recent screen is fully animated in. All other non visible content at this time are loaded now.
  This allows a smooth experience for the user and a minimal load on the first 2 steps. Especially important due that we handle
  a lot animations which are very picky when it comes to background loads. last 2 steps are async multithreaded loading tasks.

- We are using for the app icons and thumbnails a bitmap LRU cache controller to have fast access to the bitmaps we need. This improves especially
  the scrolling and as well the loading time due that allready loaded app icons are holded in the LRU cache.

- Theme support is included as well for all items the recent screen has

- Most important point: Way faster workflow now. The recent screen neither freezes the underlaying app nor it does interrupt the current process the
  user is in. It just slides over the current app about 40% of the screen. Back button as well just an outside touch (which will be passed trough to the app)
  allows to immediatelly go ahead in your workflow.

- Normal click opens an app, longpress opens app detail screen (note: we have only one hidden action on our current recents. If we later decide there could be
  other actions as well...showing a google card menu button on the top right is a very easy task and allready provided from the frameworks_opt_cards lib)
  swipe left or right removes the app from the current tasks

- Pinch to zoom out gesture provides the ability to remove all tasks with a big red warning!!

- All above mentioned actions are animated.

- As usual it is multiDpi compatible

- A lot work went into the optimizing especially for low end non gfx devices where animations
  as well listview scrolling is not that easy. We got the maximum out of optimization here which
  gives acceptable results on low end devices and amazing one on the gfx capable devices.

- A small side note this patch contains as well a fix on navigation bar preload.

Thats the short description.....user need to see it to get the real benefits of this new way.

cheers

kufi