Use apache HttpClient in lieu of the heavy ning dependency.

The ning (and transitively nettty) is a pretty heavy dependency and it would be better to have a lighter weight dependency. Based on my reading of the source we aren't making use of the additional async behaviour anyway.

Apache commons HttpClient is pretty lightweight alternative and the flient-hc library does a pretty good job of keeping thing clean, easy to read and debug.

This lowers the jar size in addition to lowering the total number of dependencies.
I don't think an interface should define a Logger instance, this should be moved into the implementing class.