f5-cli.py: Make PEP8 + Python 3 friendly
connection.py: Make PEP8 friendly

Make code easier to read and more Python 3 compatible.
autopep8 -i *.py
Reorganize, add setup.py so it can be packaged

I added a setup.py and setup.cfg so this project can be packaged into an
sdist/egg/wheel. I also moved stuff around to make it easier to package
and I converted README.md into a README.rst, because PyPI is currently
much more friendly to reST than to Markdown.

With this you should be able to:

    python setup.py install
        - or -
    python setup.py develop
        - or -
    pip install -e .
Read defaults from ~/.f5-cli.ini

Read credentials and default host from a ~/.f5-cli.ini that looks like
this:

    [defaults]
    host = my_f5

    [mt-lb]
    user = joe
    password = secret
Merge pull request #4 from msabramo/config_file

Read defaults from ~/.f5-cli.ini