* Improved temp file handling. Transfers of content can now be resumed
from temp files later; the resume does not have to be the immediate
next git-annex run.
* unused: Include partially transferred content in the list.
Rename Locations functions for better consitency, and make their values
more consistent too.
Used </> rather than manually building paths. There are still more places
that manually do so, but are tricky, due to the behavior of </> when
the second FilePath is absolute. So I only changed places where
it obviously was relative.