Updates to flup

Resolvers will now take a keyword argument, "error404", which allows you to specify a callable which will be called to render the 404 error page. Previously, you had to subclass Publisher to customize the 404 page (and it was rather low-level - basically a WSGI mini-app). The callable is called using the normal Publisher conventions. Thanks to Scot Doyle for the idea & code!

Also, I decided to look at the Python Egg thing more and converted flup's setup.py to use setuptools. (It does not require setuptools, however. It will fall back to distutils, if needed.)

From now on, the dist directory will contain an egg of the latest version of flup. (I haven't decided on a version numbering scheme yet, so it will always be 0.5. )