Support release v1.9.1

Fixes #65.

We released PhantomJS 1.9.1 about ~8 days ago. I believe this PR covers the changes necessary to support that with your Node/NPM wrapper module.

Download location (still Google Code but likely to change with the next release): https://code.google.com/p/phantomjs/downloads/list

Release announcement: https://groups.google.com/d/msg/phantomjs/K3VI5ZtGMAA/-kBTt-jSpXIJ