Ported Config.py from optparse to argparse

In this change, I've ported Config.py from using [optparse](http://docs.python.org/2/library/optparse.html) (which is now deprecated) to using [argparse](http://docs.python.org/2/library/argparse.html).

An OptionParser object used methods:

* add_option
* add_option_group
* parse_args

An OptionGroup object used:

* add_option

Both of these are replaced by ArgumentParser, which uses:

* add_argument
* add_argument_group
* parse_args

Additional cleanup in this change:
* moved positional-vs-keyword argument logic and precedence into argument setters (line 170-174, was 217-223)
* updated imports of modules (some were unused)
* changed Config to a new-style class
* updated copyright date
* removed extraneous whitespace