Refine item to do

Git can already split out a bunch of mbox files like this:

cat mailing-list/* | git mailsplit -omailing-list-messages

This gives us one file per message.  What I need to do myself is
write a tool to take those single messages and import them into the
collection, which can be done by simply moving (including renaming)
the files intelligently.
Write import script; move functions to module

Squashed commit of the following:

commit c2aa344af8f8c1977cc92ad85ccb817174cdc812
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 20:40:06 2013 +0000

    Tick off task

commit f58628e41a28628082597624779294494f20d3f6
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:41:43 2013 +0000

    Bugfix: show the correct filename

commit e4b534fee8e929b3acfe53822369907c39747ae3
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:40:16 2013 +0000

    Finish first draft of import script

commit e2041ac3b200f15654077ce6f31111cb6adad88a
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:33:26 2013 +0000

    Skip already archived messages

commit 48b17d0c5a541573cc5768b5707a633c89728578
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:31:26 2013 +0000

    Get a little further...

    Check for unarchivable messages; get hashes

commit 1971aaccfad50e3cbc941b9be19d519a2cc121f2
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:28:35 2013 +0000

    Add a bit more code...

    Nothing to write home about yet...

commit eebf6b09c5ecbb80aca9eab7adf1edc94bbe427d
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:25:07 2013 +0000

    Fix issue shoddily

    Obviously, I should fix it properly later.

commit 2350596eed9f19ec598aa2991cb73b6199a1641f
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:21:50 2013 +0000

    Revert "Verify issue"

    This reverts commit 15093b9099aac013ab84be794438813915c98b53.

commit 15093b9099aac013ab84be794438813915c98b53
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:21:13 2013 +0000

    Verify issue

    Removing the decode bit breaks the main script but fixes the importing
    one.  Curious.

commit 237cdf39de0cca57d5ae841c2786e64cbd2ba715
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 18:19:32 2013 +0000

    Fix function separation into module

commit cd107d4acfa03391f0379c688b53eab824ed288a
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 17:51:53 2013 +0000

    Start to farm out functions to module (library)

commit ca83d61594e926ba3b9602e876ac81a113ae61bf
Author: Zoë Blade <zoe@bytenoise.co.uk>
Date:   Mon Dec 9 17:41:40 2013 +0000

    Start work on import script

    Curiously, I seem to be using str.decode, which shouldn't work in
    Python 3.  I should indeed make a single library that's imported and
    used by the various individual programs, and then fix that to be
    fully for Python 3.