Update pydoc

Mark - 5.1.0 (for reals this time). Also, update copyright note on se…

…tup.py

Update summary

Release 5.0.1

Tag 5.0, update documentation, update versions

rerelease 4.2.1 as 4.2.2 to work around pypi issue

Use platform-independent os.sep and os.devnull instead of POSIX value…

…s to hopefully be able to support windows