Update to rust master

Author: alexcrichton

src/json.rs

@@ -2545,7 +2545,6 @@ mod tests {
                 StackElement, Stack, Decoder, Encoder, EncoderError};
     use std::{i64, u64, f32, f64};
     use std::collections::BTreeMap;
-    use std::num::Float;
     use std::string;
 
     #[derive(RustcDecodable, Eq, PartialEq, Debug)]

src/lib.rs

@@ -14,7 +14,7 @@
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/rustc-serialize/")]
 #![cfg_attr(test, deny(warnings))]
-#![cfg_attr(test, feature(test, std_misc))]
+#![cfg_attr(test, feature(test))]
 #![allow(trivial_numeric_casts)]
 
 #[cfg(test)] extern crate test;