Tweak the interface of std::io

* Reexport io::mem and io::buffered structs directly under io, make mem/buffered
  private modules
* Remove with_mem_writer
* Remove DEFAULT_CAPACITY and use DEFAULT_BUF_SIZE (in io::buffered)

src/test/bench/core-std.rs

@@ -70,7 +70,7 @@ fn shift_push() {
 }
 
 fn read_line() {
-    use std::io::buffered::BufferedReader;
+    use std::io::BufferedReader;
 
     let mut path = Path::new(env!("CFG_SRC_DIR"));
     path.push("src/test/bench/shootout-k-nucleotide.data");

src/test/bench/shootout-fasta.rs

@@ -15,8 +15,7 @@
  */
 
 use std::io;
-use std::io::buffered::BufferedWriter;
-use std::io::File;
+use std::io::{BufferedWriter, File};
 use std::num::min;
 use std::os;
 

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

@@ -145,10 +145,7 @@ fn make_sequence_processor(sz: uint,
 
 // given a FASTA file on stdin, process sequence THREE
 fn main() {
-    use std::io::Reader;
-    use std::io::stdio;
-    use std::io::mem::MemReader;
-    use std::io::buffered::BufferedReader;
+    use std::io::{stdio, MemReader, BufferedReader};
 
     let rdr = if os::getenv("RUST_BENCH").is_some() {
         let foo = include_bin!("shootout-k-nucleotide.data");

src/test/bench/shootout-mandelbrot.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::io::buffered::BufferedWriter;
+use std::io::BufferedWriter;
 
 struct DummyWriter;
 impl Writer for DummyWriter {

src/test/bench/sudoku.rs

@@ -16,7 +16,7 @@ extern mod extra;
 
 use std::io;
 use std::io::stdio::StdReader;
-use std::io::buffered::BufferedReader;
+use std::io::BufferedReader;
 use std::os;
 use std::unstable::intrinsics::cttz16;
 use std::vec;

src/test/run-pass/auto-encode.rs

@@ -34,7 +34,7 @@ fn test_ebml<'a, A:
     Encodable<EBWriter::Encoder> +
     Decodable<EBReader::Decoder<'a>>
 >(a1: &A) {
-    let mut wr = std::io::mem::MemWriter::new();
+    let mut wr = std::io::MemWriter::new();
     let mut ebml_w = EBWriter::Encoder(&mut wr);
     a1.encode(&mut ebml_w);
     let bytes = wr.get_ref();

src/test/run-pass/capturing-logging.rs

@@ -16,7 +16,7 @@
 extern mod native;
 
 use std::fmt;
-use std::io::comm_adapters::{PortReader, ChanWriter};
+use std::io::{PortReader, ChanWriter};
 use std::logging::{set_logger, Logger};
 
 struct MyWriter(ChanWriter);

src/test/run-pass/deriving-encodable-decodable.rs

@@ -18,7 +18,7 @@
 
 extern mod extra;
 
-use std::io::mem::MemWriter;
+use std::io::MemWriter;
 use std::rand::{random, Rand};
 use extra::serialize::{Encodable, Decodable};
 use extra::ebml;

src/test/run-pass/ifmt.rs

@@ -14,9 +14,8 @@
 #[deny(warnings)];
 
 use std::fmt;
-use std::io::mem::MemWriter;
+use std::io::MemWriter;
 use std::io;
-use std::io::Writer;
 use std::str;
 
 struct A;