Log message:
Improve EGG_NAME default to work for packages with '-' in their name.
Remove now unnecessary overrides in various packages.

Fix various problems while here, including marking packages as not ready
for python-3.x.

Log message:
Import py-scikit-learn-0.15.2.

scikit-learn is a Python module integrating classic machine learning
algorithms in the tightly-knit scientific Python world (numpy, scipy,
matplotlib). It aims to provide simple and efficient solutions to
learning problems, accessible to everybody and reusable in various
contexts: machine-learning as a versatile tool for science and
engineering.