[Distutils] Revision control plugin support for setuptools

[Phillip J. Eby]

I've just checked in support for revision control plugins in 
setuptools.  This means that folks using any of the various revision 
control systems out there other than CVS and SVN can now write a plugin for 
setuptools to support automatically finding data and source files when 
building packages and their source distributions.

Please see setuptools.txt in the source for documentation, and let me know 
if you have any questions or problems.