DSTify [T]/str extension traits

This PR changes the signature of several methods from `foo(self, ...)` to
`foo(&self, ...)`/`foo(&mut self, ...)`, but there is no breakage of the usage
of these methods due to the autoref nature of `method.call()`s. This PR also
removes the lifetime parameter from some traits (`Trait<'a>` -> `Trait`). These
changes break any use of the extension traits for generic programming, but
those traits are not meant to be used for generic programming in the first
place. In the whole rust distribution there was only one misuse of a extension
trait as a bound, which got corrected (the bound was unnecessary and got
removed) as part of this PR.

[breaking-change]

src/libstd/ascii.rs

@@ -15,6 +15,7 @@
 #![experimental]
 
 use collections::Collection;
+use core::kinds::Sized;
 use fmt;
 use iter::Iterator;
 use mem;
@@ -272,7 +273,7 @@ impl OwnedAsciiCast for Vec<u8> {
 
 /// Trait for converting an ascii type to a string. Needed to convert
 /// `&[Ascii]` to `&str`.
-pub trait AsciiStr {
+pub trait AsciiStr for Sized? {
     /// Convert to a string.
     fn as_str_ascii<'a>(&'a self) -> &'a str;
 
@@ -291,13 +292,13 @@ pub trait AsciiStr {
     fn to_uppercase(&self) -> Vec<Ascii>;
 
     /// Compares two Ascii strings ignoring case.
-    fn eq_ignore_case(self, other: &[Ascii]) -> bool;
+    fn eq_ignore_case(&self, other: &[Ascii]) -> bool;
 }
 
-impl<'a> AsciiStr for &'a [Ascii] {
+impl AsciiStr for [Ascii] {
     #[inline]
     fn as_str_ascii<'a>(&'a self) -> &'a str {
-        unsafe { mem::transmute(*self) }
+        unsafe { mem::transmute(self) }
     }
 
     #[inline]
@@ -321,7 +322,7 @@ impl<'a> AsciiStr for &'a [Ascii] {
     }
 
     #[inline]
-    fn eq_ignore_case(self, other: &[Ascii]) -> bool {
+    fn eq_ignore_case(&self, other: &[Ascii]) -> bool {
         self.iter().zip(other.iter()).all(|(&a, &b)| a.eq_ignore_case(b))
     }
 }
@@ -372,7 +373,7 @@ pub trait OwnedAsciiExt {
 }
 
 /// Extension methods for ASCII-subset only operations on string slices
-pub trait AsciiExt<T> {
+pub trait AsciiExt<T> for Sized? {
     /// Makes a copy of the string in ASCII upper case:
     /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
     /// but non-ASCII letters are unchanged.
@@ -386,10 +387,10 @@ pub trait AsciiExt<T> {
     /// Check that two strings are an ASCII case-insensitive match.
     /// Same as `to_ascii_lower(a) == to_ascii_lower(b)`,
     /// but without allocating and copying temporary strings.
-    fn eq_ignore_ascii_case(&self, other: Self) -> bool;
+    fn eq_ignore_ascii_case(&self, other: &Self) -> bool;
 }
 
-impl<'a> AsciiExt<String> for &'a str {
+impl AsciiExt<String> for str {
     #[inline]
     fn to_ascii_upper(&self) -> String {
         // Vec<u8>::to_ascii_upper() preserves the UTF-8 invariant.
@@ -422,7 +423,7 @@ impl OwnedAsciiExt for String {
     }
 }
 
-impl<'a> AsciiExt<Vec<u8>> for &'a [u8] {
+impl AsciiExt<Vec<u8>> for [u8] {
     #[inline]
     fn to_ascii_upper(&self) -> Vec<u8> {
         self.iter().map(|&byte| ASCII_UPPER_MAP[byte as uint]).collect()