Update pjax to 1.7.0

Update the pjax lib to 1.7.0
File pull from https://github.com/defunkt/jquery-pjax/tags
Minify manually using uglifyjs
npm test pass

![screen shot 2013-06-09 at 6 09 47 pm](https://f.cloud.github.com/assets/664857/629721/80674eb8-d16a-11e2-8e1e-9a795991f7c2.png)