sourced coffee generated js lib from node-beanstalk-client
sourced test from node-beanstalk-client
refactored lib and test

- coffee generated js into readable js
- primitive test script into mocha test cases
added support for utf8 job strings
bug fix - the stream data corresponding to subsequent responses were cleared after handling a response
refactored response handler
api - directly exporting the client
added basic documentation
propagating stream errors to callbacks