Add missing features

Author: alexcrichton

src/lib.rs

@@ -10,7 +10,7 @@
 
 //! Support code for encoding and decoding types.
 
-#![feature(core, collections, unicode, io, std_misc, path)]
+#![feature(core, collections, unicode, io, std_misc, path, hash, os)]
 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/rustc-serialize/")]