Fix phantomjs dependency issues with (1) mac and (2) node 0.10.x

phantomjs npm package installation issues

1. With phantomjs 1.8.2, the mac zip file format changed causing this issue https://github.com/Obvious/phantomjs/issues/15 and related issue https://github.com/gruntjs/grunt-lib-phantomjs/issues/17
2. With node 0.10.x phantomjs' npm package (https://github.com/Obvious/phantomjs) install fails due to an issue with unzipping, see https://github.com/Obvious/phantomjs/issues/34