- Option -R should not have to be separated from the rest,
  such that "jdupes -dR testdir", "jdupes -d -R testdir",
  "jdupes -Rd testdir", etc., all yield the same results.

- Add option to highlight or identify symlinked files (suggest
  using --classify to identify symlinks with @ suffix... when
  specified, files containing @ are listed using \@).

- Consider option to match only to files in specific directory.

- Add a way to store stat() info + inital and full hashes for
  explicit loading in future runs to speed up repeated calls to
  the program.

- The --xsize option can be improved. Instead of simply specifying an
  exclusion size min/max, the option should offer multiple ways to
  specify allowed file sizes. Examples:
  - '--xsize=512-1024' only examine files between 512 and 1024 bytes
  - '--xsize=1M-3M,+20M' examine files 1-3 MB and >20 MB in size
