Fixes #54

If a new directory is found in incoming but the move operation to
processing failed for some reason, the timestamp and username
directories (and potentially some partially moved data?) would remain
in processing. To prevent confusion about those "incomplete" transfer
candidates they are moved to the "ERROR" location.

All projects (and namespaces) should start with an "ATx" prefix, having
a capital "AT" and a lowercase "x".

All outputs of any kind of duration should be using a human readable
variant of the time span.

Fixes #25

This allows us to re-use the summary method in other tools like the tray
application.

CreateNewDirectory, CheckForDirectory and CollectOrphanedFiles.

Fixes #24