First stab at using setuptools >= 0.7 instead of distribute.

My doctest / renormalizer fu is not strong enough to deal with the
changes to output:

- setuptools now has dependencies, and emits output to add them as
  'find-links'.  I tried adding an 'adding_find_link' renormalizer,
  but it doesn't suppress the output.

- Other failures due to merge tweaking APIs, etc.  Again, I'm not
  competent to fix them in the doctest / renormalizer world:  they make
  my head hurt.