handle case when directory is removed from drop upload directory

[dawuud]

We need to handle the case where a directory is removed or moved out of the drop uploader directory. Specifically this case needs to be specially handled only when the sub-directory was moved into the drop uploader directory and a inotify watch for that sub-directory was added. Further investigation is needed to determine the proper way to remove this inotify watch.

So far it seems that we will respond to either the IN_DELETE_SELF or IN_MOVE_SELF events for each of these sub-directory inotify "watches".