No rate limiting in example.

Giving up on implementing rate limiting. Much harder than I thought for
just an example application.
Dirty commit. Rewriting a lot of the components.

In progress, tests won't pass.
Lots of optimizations, done with ProgressBar. WIP.

Still dirty.
Forgot to change tests for deque.
Done with bits and bytes progress bars.

Still dirty.
Done with wget.

For performance reasons, no longer using smooth bitrate on every
iteration. In actuality this is closer to the real wget.
Finally done with refactoring.
Removing whitespace.