Fix many style and format warnings from the flake8 tool.

This makes us more conformant with PEP 8.
Warnings caused by using tabs instead of spaces have not been
fixed.  For now, we can just write a config file to ignore
them.
remove unused imports
Clean up logging

Remove several return statements, log the word that describes the
logging level as well as the symbol and add a module-level doc string
drop cookie support from the command line interface

As of this writing, bugzilla 4.4, which is current stable and bugzilla
4.2, which is old stable, have dropped support for login cookies for
security reasons.
Add configuration file for flake8 and tox

Currently this is here so we can use flake8 to test for pep8 compliance.
However, if someone wants to write tox tests for pybugz, pull requests
are welcome.
make calls to call_bz consistent

Instead of passing dictionary literals, always pass a dictionary named
params to call_bz.
Do not discard summary in bugz post

When bugz post prompted for a summary, it wasn't saving the summary to
the connection which means the summary was being discarded.
Process the skip_auth setting in the connection
Log the connection dump before the last info message