[Csv] code review

[Skip Montanaro]

Neal,

Thanks for the feedback.  We'll work on the items you indicated.  I can
answer one item right now:

    * is CSV going to be maintained outside the python tree?
      If not, remove the 2.2 compatibility macros for:
             PyDoc_STR, PyDoc_STRVAR, PyMODINIT_FUNC, etc.

We don't intend to maintain it outside the Python tree, however
compatibility with 2.2 is still desirable, so I think we'll leave those
macros in place.  I'll add a comment to the top of the code about that.

Skip