Improving namespacing strategy and remove unneeded middleware

This replaces all `YUI.Env.PNM` namespaces with `[global].PNM` to
decouple them from YUI and when YUI is loaded in the browser.

The expose-* middleware has been removed now that it's unneeded because
express-state provides a simple API for exposing data to the client.
Update dependencies and bump version to 0.9.0