ModeManager: Force use of static interface

Change-Id: I314ca347fd0fad30bf5ac6a6d4c67db8e5687065
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Core: Small cleanups

Change-Id: Id85ef2e53f42fd934716d07e1bfc7ec14a59f878
Reviewed-by: Kurt Pattyn <pattyn.kurt@gmail.com>
Reviewed-by: hjk <hjk121@nokiamail.com>