Launcher3: implement hidden app feature

abc ezio84: port to omnirom launcher3

Allow user to hide/show app on the app drawer using multi-selection.
To do that a custom app filter class will be used.
By clicking the check menu item selected app will be added to the hide
list set. On back pressed no changes will be applied.

Change-Id: I64387fcc399eef0c8d9fe9b4b36c11646143f40b
Signed-off-by: enricocid <enrico2588@gmail.com>

Launcher3: Fix incorrect string value

Change-Id: I044bd0c81fa88d510ba47c86f6cb1e8f4bc0374f
29 files changed