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.

src/header/common/accept_language.rs

@@ -1,4 +1,4 @@
-use header::{self, QualityItem};
+use header::QualityItem;
 use std::str::FromStr;
 use std::fmt;
 
@@ -49,7 +49,6 @@ impl_list_header!(AcceptLanguage,
 #[cfg(test)]
 mod tests {
     use header::{Header, qitem, Quality, QualityItem};
-
     use super::*;
 
     #[test]