The setup.py contained in 5.1-RC1 and -RC2 does not
work with Python-1.5 (and perhaps 1.6), additionally it
does its work in a rather complex way that makes it
impossible to use the full functionality of Distutils,
e.g. the creation of RPM-packages does not work.
This new version changes the name of some command-line
--install-header becomes --install-headers
--install-source becomes --install-data