hashdeep-compare function: sort

Sorts the entries in a hashdeep log by file path.

Syntax:
    hashdeep-compare sort path/to/unsorted_input.txt path/to/sorted_output.txt

Notes:
    hashdeep does not guarantee ordering of log entries, and ordering tends to
    be inconsistent between runs in practice. Sorting allows comparison of
    hashdeep logs in a text-diff tool, which may be the easiest way to compare
    logs with uncomplicated differences.

    Note that if the output file already exists, the command will be aborted
    (hashdeep-compare will not overwrite existing files).

