Tasks stop on unmanaged

stop tasks when entities are unmanaged, and better bookkeeping for scheduled tasks.
(also fixes eclipse IDE problems caused by checkstyle.)
I can see why we'd want to do this when shutting down (or clearing state when transitioning to "failed"), but is this the right thing to do in normal situation when location is being unmanaged? Will the parent still have a reference to the unmanaged location in its `getChildren()`?