Refactor for issue #57

@cldwalker this code can be further refactored, but I wanted to run the changes by you before it diverged from cldwalker/master further.  Could you look it over and let me know what you think?

Overview: 

- `rdebug_test_slow.rb` is a test for rdebug that will drop-in to your master branch (along with the two supporting files `simple_class.rb` and `simple_loop.rb`).  To be compatible with rdebug unmodified, it calls the rdebug executable with backticks and spawn.  Unfortunately, that means that the client/server test has to loop on creating the client connection until the server has started up.

- `rdebug_option_parser_test.rb` is only for the extracted class RdebugOptionParser in eric-hu/master.  There's only a few tests in there right now, but others can be made in the same vein fairly easily, so long as this approach is acceptable.