Added argparser and --debug flag option

With the ArgumentParser, we can now add new command line flags as needed.  The
first flag added was a --debug option, which will enable debug output in the Map
and Game classes (for now).  This will default to false unless the flag is specified.
Directly call args.debug instead of storing value

Fixes #18
Merge pull request #29 from ChodeGames/command_line_args

Added argparser and --debug flag option