better handling of client stream termination

1. Pass an error to an active query if the client is ended while a query is in progress.
2. actually emit 'end' event on the client when the stream ends
3. do not emit an error from native bindings if lasterror is null
pin jshint version
use supplied connection params in new tests
Merge pull request #315 from brianc/handle-stream-end

better handling of client stream termination