fix windows build to work with new setup.py

refs #1884
setup.py: set long_description by reading in the README
'qrcode' needs 'six' but its setup.py does not install it

KeySync might use 'six' in the future as well. Also, I fixed the alphasort
on the dependencies list.
REBASE setup.py: set long_description...
setup.py: if using Python < 2.7, then include 'argparse' as dep

argparse was added to the standard Python libraries in Python 2.7, so if
KeySync is running on an older version of Python, then be sure that
argparse is installed.