Make script portable

- Better tests for autoloading, based on the strategy employed by
  PHPUnit (test a number of well-known locations for Composer's
  autoloader).
- Added file-level docblock
More portable configuration handling

- Use Zend\Console\Getopts:
  - to allow passing a configuration file
  - to allow passing individual options via CLI
  - to report available options
Merge branch 'feature/portability'

Close #8