Kit: Add static method to get icon for a path

Change-Id: Icd15e53022453be0713ee4953dd8f1f099b053de
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
KitManager: Use static API as other singletons do

Change-Id: Ia49c6552a5aae72870687ef9c64f2642fbe24155
Reviewed-by: hjk <hjk121@nokiamail.com>