Fixed a number of pylint issues - many more to go.  Have to balance
pylint's config with the default Google style conventions.

Info on how to use tox.  Well, just telling people to run tox, not a
huge amount of info there.

Add pylint config file.  Clean up some pylint errors.  Clean up setup.py
and make it work with tox/pip.

Now using reStructuredText. Cleaned up a few text errors.  Added link to
travis test status.

setup.py changes:
  Add test and dist_clean commands.
  Add MANIFEST.in file to make sdist command work.
Test changes:
  Remove unneeded runall.py script.  Also, __init__.py.
  Mentioned tests and how to run them in README.

Project to check correctness of system crontab files.  On most
cron implementations these would be the /etc/crontab file and
files in /etc/cron.d