Fix and improve switching applications

v2: (Tadao Tanikawa)
   Minor fixed pointed by reveiw and organize debug message

v1: (Tadao Tanikawa)
Quick hack to fix and improve switching applications.

Changes:

 * Improve management of layers and surfaces
   Previously single layer was shared among all applications,
   now each application has its own layer.

 * Improve showing / hiding applications
   Previously to show/hide application, surfaces are added
   or removed everytime, but it's slow.
   Now reordering layers controls showing/hiding applications,
   it much faster.

 * Shortcut icons whose application is not installed no
   longer cause issue to switch apps.

Caution:
   This patch is very quick hack, and many old codes which
   regarding to management surfaces are disabled, so there
   may be unnoticed degraded.

Change-Id: I69494213b0d1b169558f3d792ebecf414caccacc
Signed-off-by: Tadao Tanikawa <tanikawa.tadao@jp.panasonic.com>