[Distutils] do-nothing fails

[Paul F. Dubois]

Allow me to confess that the following low-priority bug actually bit me:

You can't have packages be an empty list. The build directory does not get
created and the installer complains it can't copy the tree.

Why might I be running distutils to install "nothing"? The CXX package
consists of header files and some C and C++ source files; no python files or
extension modules at the moment. I propose to put the source files (needed
by a builder of a CXX extension) into PYTHON/etc/CXX. The include files get
treated like Numeric's.

I can obviously work around this but it is a generally nice idea that end
cases work.