Some more fixes to how we deal with finding Cython extension files.  This ensures that the search only goes down the paths for actual packages relevant to the project.  I'm not *sure* if or how this will affect affiliated packages.  But in general I think this is desirable behavior.
Add support for the setup.py test command (which astropy_helpers itself does not use, but other projects can and should, though it requires astropy to be installed).