feat(hyper): switch to std::io, std::net, and std::path.

All instances of `old_io` and `old_path` were switched to use the new
shiny `std::io`, `std::net`, and `std::path` modules. This means that
`Request` and `Response` implement `Read` and `Write` now.

Because of the changes to `TcpListener`, this also takes the opportunity
to correct the method usage of `Server`. As with other
languages/frameworks, the server is first created with a handler, and
then a host/port is passed to a `listen` method. This reverses what
`Server` used to do.

Closes #347

BREAKING CHANGE: Check the docs. Everything was touched.

examples/server.rs

@@ -1,9 +1,9 @@
-#![feature(old_io)]
+#![feature(io, net)]
 extern crate hyper;
 #[macro_use] extern crate log;
 
-use std::old_io::util::copy;
-use std::old_io::net::ip::Ipv4Addr;
+use std::io::{Write, copy};
+use std::net::IpAddr;
 
 use hyper::{Get, Post};
 use hyper::header::ContentLength;
@@ -50,7 +50,7 @@ fn echo(mut req: Request, mut res: Response) {
 }
 
 fn main() {
-    let server = Server::http(Ipv4Addr(127, 0, 0, 1), 1337);
-    let _guard = server.listen(echo).unwrap();
+    let server = Server::http(echo);
+    let _guard = server.listen(IpAddr::new_v4(127, 0, 0, 1), 1337).unwrap();
     println!("Listening on http://127.0.0.1:1337");
 }