- Added by department and by unit download stats pages.

- Switched to different country codes for different classes of local traffic, ...

and to fix the problem of download numbers being assigned to the wrong class.

- Added makefile. ...

- Removed redundant and duplicated files.
- Added database function to retrieve date stats were last generated, and
  included this in the header.
- Made styling consistent with otago_eprints.

- Re-added statistics files in a better location.