Frameworks: QS performance profiles tile

Patchset 2: Fix not null comparation
Patchset 3: xxhdpi drawables
Patchset 4: Fix xxhdpi drawables (thx blunden)
            Rebased
Patchset 5: Add suggestions
            Sync on boot the system property with the setting
Patchset 6: Rebased
Patchset 7: Rebased (solved conflict with config.xml)

Change-Id: Ib32d3734b63f88a3473e0ab10d8edf30dae9ceb6
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>