Siesta/phantomjs: Disable console output

[krullj]

Our application outputs a lot of information to console, but when I'm running the tests through phantomjs, I would prefer to just see which tests passed and failed, along with the summary information.

[krullj]

It's a fairly simple change, so please see the attached patch file to be applied to bin/phantomjs-launcher.js. Sorry it's not a patch file by default, but the forums wouldn't allow that file type as an attachment.