std::io: Add Buffer.lines(), change .bytes() api

-   `Buffer.lines()` returns `LineIterator` which yields line using
    `.read_line()`.
-   `Reader.bytes()` now takes `&mut self` instead of `self`.
-   `Reader.read_until()` swallows `EndOfFile`. This also affects
    `.read_line()`.

src/test/bench/core-std.rs

@@ -77,8 +77,7 @@ fn read_line() {
 
     for _ in range(0, 3) {
         let mut reader = BufferedReader::new(File::open(&path).unwrap());
-        while !reader.eof() {
-            reader.read_line();
+        for _line in reader.lines() {
         }
     }
 }

src/test/bench/shootout-k-nucleotide-pipes.rs

@@ -188,14 +188,7 @@ fn main() {
    // reading the sequence of interest
    let mut proc_mode = false;
 
-   loop {
-       let line = {
-           let _guard = io::ignore_io_error();
-           match rdr.read_line() {
-               Some(ln) => ln,
-               None => break,
-           }
-       };
+   for line in rdr.lines() {
        let line = line.trim().to_owned();
 
        if line.len() == 0u { continue; }

src/test/bench/sudoku.rs

@@ -18,7 +18,6 @@ use std::io;
 use std::io::stdio::StdReader;
 use std::io::buffered::BufferedReader;
 use std::os;
-use std::uint;
 use std::unstable::intrinsics::cttz16;
 use std::vec;
 
@@ -72,10 +71,7 @@ impl Sudoku {
         assert!(reader.read_line().unwrap() == ~"9,9"); /* assert first line is exactly "9,9" */
 
         let mut g = vec::from_fn(10u, { |_i| ~[0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8] });
-        loop {
-            let line = match reader.read_line() {
-                Some(ln) => ln, None => break
-            };
+        for line in reader.lines() {
             let comps: ~[&str] = line.trim().split(',').collect();
 
             if comps.len() == 3u {