fix(rustup): rustc 1.0.0-nightly (123a754cb 2015-03-24)

* fix `extern crate` declaration for rustc-serialize
* enable `into_cow` feature
* replace as_slice() calls by as_ref and enable `convert` feature
* use `core` feature in doc tests

src/status.rs

@@ -20,6 +20,7 @@ use std::cmp::Ordering;
 /// `self.class().default_code()`:
 ///
 /// ```rust
+/// #![feature(core)]
 /// # use std::num::FromPrimitive;
 /// # use hyper::status::StatusCode;
 /// let statusopt: Option<StatusCode> = FromPrimitive::from_u16(137u16);
@@ -357,19 +358,19 @@ impl Copy for StatusCode {}
 ///
 /// ```rust
 /// # use hyper::status::StatusCode::{ImATeapot, Unregistered};
-/// assert_eq!(format!("{}", ImATeapot).as_slice(),
-///            "418 I'm a teapot");
-/// assert_eq!(format!("{}", Unregistered(123)).as_slice(),
+/// assert_eq!(format!("{}", ImATeapot), "418 I'm a teapot");
+/// assert_eq!(format!("{}", Unregistered(123)),
 ///            "123 <unknown status code>");
 /// ```
 ///
 /// If you wish to just include the number, convert to `u16` instead:
 ///
 /// ```rust
+/// #![feature(core)]
 /// # use std::num::ToPrimitive;
 /// # use hyper::status::StatusCode::{ImATeapot, Unregistered};
-/// assert_eq!(format!("{}", ImATeapot.to_u16().unwrap()).as_slice(), "418");
-/// assert_eq!(format!("{}", Unregistered(123).to_u16().unwrap()).as_slice(), "123");
+/// assert_eq!(format!("{}", ImATeapot.to_u16().unwrap()), "418");
+/// assert_eq!(format!("{}", Unregistered(123).to_u16().unwrap()), "123");
 /// ```
 impl fmt::Display for StatusCode {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {