Command line UI cleanup and packaging additions.

- Added a setup.py.
- Added README.txt and LICENSE.txt files.
- Setup a Makefile for building and cleanup.

csvsql command changes:

- Added a complete set of CSV import and export command line options for
  customizing the reader and writer objects from Python's 'csv' module.
- Reworked the command line options to be cleaner and make more sense.
- Added more error handling and reporting for common edge cases.

csvsql.py module changes:

- The import_csv() class method now throws an IOError if it's output path
  already exists.
- Added the 'db_path' property to the csvsql class.