add comment: replace os.path.join import with something different. confusing with str.join
improve error message for old Python versions
remove commas for implicit string continuation
implicit string continuation
if length of version tuple is 2 then the micro version number must be zero
make sure user can read warnings before distutils spits out its output
with keyword not available for Python 2.4, make certain that users with old Python can at least run setup.py