Hm, crazy idea...

So...I wonder if any one else would want to be able to tag *other*
people's media with their own separate set of tags. Delicious does
this by accident because every page can be bookmarked by anyone,
and you can view everyone's bookmarks for a given link, but I don't
know of other services that do this on purpose.

Some things that we tag are pretty cut and dry, so there probably
won't be much variation of tags from one person to another. Links
are a good example. A news story about a startup donut shop down
the street fits rather specifically into one's perception.

But art is different. Art is *supposed* to hit people different
ways. I imagine that stuff people put on their gmg instance will be
art, and that visitors will experience a user's media in different
ways. Let's allow for that

Make it so that each StorageInterface implementation has it's own
submodule.

e.g.

::

    - mediagoblin/  
        - storage/  
           - cloudfiles.py  
           - mountstorage.py  
           - basicfile.py

"medium" and "thumbnail" versions of JPEG files are stored with a
lowercase ".jpg" name extension, but the original versions are
stored with whatever case was in the original file name: jpg, JPG,
jpG…

So you get something like this:

::

    user_dev/media/public/media_entries/fa23ab31abf7ec67be8000001:
     originalFileName.JpG
     medium.jpg
     thumbnail.jpg

(If the file has a random extension like "dfsg", it is simply not
accepted.)

The extension should be made lowercase, so that all sizes have the
same extension both on disk and when downloading.