Print out debugger port

This way we can connect to the debugger from an external program like
node-inspector
Don't spawn a debugger, allow user to attach their own
Allow specifying a debug port, or default to port 5858
Update optparse to version 1.0.4

Fixes a bug in parsing args that end with an optional parameter.
Update README with new debugging info
Update readme.
Update changes.
Require user to specify a debug port when using --debug option and exit if user
passes in an invalid port.