refactor(http): merge Request and Response from server and client

Request and Response are now visible from:
- hyper::{Request, Response}
- hyper::server::{Request, Response}
- hyper::client::{Request, Response}
They truly exist in the http module, but are re-exported to reduce the number of breaking changes.

request::new and response::new were renamed to ::from_wire to reduce confusion with Request::new
and Response::new. See issue #1126

Request now has an optional Body, because not all requests have bodies.
Use body_ref() to determine if a body exists.
Use body() to take the body, or construct one if no body exists.

Closes #1155

BREAKING CHANGE: Response::body() now consumes the response

src/http/mod.rs

@@ -24,6 +24,8 @@ mod io;
 mod h1;
 //mod h2;
 mod str;
+pub mod request;
+pub mod response;
 
 /*
 macro_rules! nonblocking {