Add Glacier guide

> Do we need all these above? They look very similar to what you'd expect in the Javadoc.

You are right about this, I think I should remove this and extend the javadoc instead.

> Would it make more sense to have more examples here?

> I'd wait for now to see if somebody asks for something more specific in the mail list. I'd like to have examples covering the most common questions, but for now I think this basic example and the examples in jclouds-examples are enough.