More Rust updates:

- Some stray deriving -> derive changes
- use::{mod} -> use::{self}
- fmt.write -> fmt.write_str

This does not catch the last case of fmt.write_str in the
Show impl of a Header Item. This will need to be changed
separately.

src/header/common/authorization.rs

@@ -1,5 +1,6 @@
-use std::fmt::{mod, Show};
+use std::fmt::{self, Show};
 use std::str::{FromStr, from_utf8};
+use std::ops::{Deref, DerefMut};
 use serialize::base64::{ToBase64, FromBase64, Standard, Config, Newline};
 use header::{Header, HeaderFormat};
 
@@ -7,13 +8,15 @@ use header::{Header, HeaderFormat};
 #[derive(Clone, PartialEq, Show)]
 pub struct Authorization<S: Scheme>(pub S);
 
-impl<S: Scheme> Deref<S> for Authorization<S> {
+impl<S: Scheme> Deref for Authorization<S> {
+    type Target = S;
+
     fn deref<'a>(&'a self) -> &'a S {
         &self.0
     }
 }
 
-impl<S: Scheme> DerefMut<S> for Authorization<S> {
+impl<S: Scheme> DerefMut for Authorization<S> {
     fn deref_mut<'a>(&'a mut self) -> &'a mut S {
         &mut self.0
     }