* Find a way to work with stdin so shell scripters can feed text to
  dupekill and it can figure out what to do
* If given a list, let dupekill determine if it's a directory or a file.
  If a directory, check every file in it. If a file, add it to the list of
  files to be inspected. This will likely require a refactor
* An option to turn duped files into hardlinks

Refactored feature-set:

- Dry run / ask user
- ignore symlinks
- recursive
- interactive
- keep newer files
- keep older files
- verbose