Make .wait() use 'id' type instead of 'options'.

Wait requires an id url param.
container.wait doesn't stream data.

It does send json when the container exits which
is useful to get back in a parsed form.
Fix wait success code.

The API docs suggest that this should be
204 on success, but testing against docker 0.6.3
I get 200 responses.
Merge pull request #15 from psanford/fix_wait

Make .wait() use 'id' type instead of 'options'.