Allow user-installed apps to be disabled and force stop when disabling an app

In more detail, this patch will change the following:

* Users can disable regularly installed apps.
While disabled, the app can be uninstalled or enabled again.

* When disabling an app (user or system), force close the
application.

* System apps can be disabled, or installed updates can be uninstalled.
Previous behavior only allowed updates to be uninstalled,
then be disabled.

Signed-off-by: Roman Birg <romanbirg@gmail.com>