windows: Allow listing directory trees in *_artifacts
windows: Don't install pip or Python dependencies into system path
windows: Build msgpack-python
windows: Install all Python modules into lib/python/
windows: Add libxml2
windows: Add libxslt
windows: Add lxml
windows: Add six, python-dateutil, requests
windows: Add VMNetX

Currently requires Git master version, and doesn't work.
windows: Drop spicy.exe from bdist