Easier interface for TCP ::connect and ::bind.

Prior to this commit, TcpStream::connect and TcpListener::bind took a
single SocketAddr argument. This worked well enough, but the API felt a
little too "low level" for most simple use cases.

A great example is connecting to rust-lang.org on port 80. Rust users would
need to:

  1. resolve the IP address of rust-lang.org using
     io::net::addrinfo::get_host_addresses.

  2. check for errors

  3. if all went well, use the returned IP address and the port number
     to construct a SocketAddr

  4. pass this SocketAddr to TcpStream::connect.

I'm modifying the type signature of TcpStream::connect and
TcpListener::bind so that the API is a little easier to use.

TcpStream::connect now accepts two arguments: a string describing the
host/IP of the host we wish to connect to, and a u16 representing the
remote port number.

Similarly, TcpListener::bind has been modified to take two arguments:
a string describing the local interface address (e.g. "0.0.0.0" or
"127.0.0.1") and a u16 port number.

Here's how to port your Rust code to use the new TcpStream::connect API:

  // old ::connect API
  let addr = SocketAddr{ip: Ipv4Addr{127, 0, 0, 1}, port: 8080};
  let stream = TcpStream::connect(addr).unwrap()

  // new ::connect API (minimal change)
  let addr = SocketAddr{ip: Ipv4Addr{127, 0, 0, 1}, port: 8080};
  let stream = TcpStream::connect(addr.ip.to_str(), addr.port()).unwrap()

  // new ::connect API (more compact)
  let stream = TcpStream::connect("127.0.0.1", 8080).unwrap()

  // new ::connect API (hostname)
  let stream = TcpStream::connect("rust-lang.org", 80)

Similarly, for TcpListener::bind:

  // old ::bind API
  let addr = SocketAddr{ip: Ipv4Addr{0, 0, 0, 0}, port: 8080};
  let mut acceptor = TcpListener::bind(addr).listen();

  // new ::bind API (minimal change)
  let addr = SocketAddr{ip: Ipv4Addr{0, 0, 0, 0}, port: 8080};
  let mut acceptor = TcpListener::bind(addr.ip.to_str(), addr.port()).listen()

  // new ::bind API (more compact)
  let mut acceptor = TcpListener::bind("0.0.0.0", 8080).listen()

[breaking-change]

src/compiletest/runtest.rs

@@ -19,7 +19,6 @@ use util;
 
 use std::io::File;
 use std::io::fs;
-use std::io::net::ip::{Ipv4Addr, SocketAddr};
 use std::io::net::tcp;
 use std::io::process::ProcessExit;
 use std::io::process;
@@ -316,10 +315,7 @@ fn run_debuginfo_gdb_test(config: &config, props: &TestProps, testfile: &Path) {
                 //waiting 1 second for gdbserver start
                 timer::sleep(1000);
                 let result = task::try(proc() {
-                    tcp::TcpStream::connect(SocketAddr {
-                        ip: Ipv4Addr(127, 0, 0, 1),
-                        port: 5039,
-                    }).unwrap();
+                    tcp::TcpStream::connect("127.0.0.1", 5039).unwrap();
                 });
                 if result.is_err() {
                     continue;

src/libstd/io/mod.rs

@@ -83,11 +83,9 @@ Some examples of obvious things you might want to do
 
     ```rust,should_fail
     # #![allow(unused_must_use)]
-    use std::io::net::ip::SocketAddr;
     use std::io::net::tcp::TcpStream;
 
-    let addr = from_str::<SocketAddr>("127.0.0.1:8080").unwrap();
-    let mut socket = TcpStream::connect(addr).unwrap();
+    let mut socket = TcpStream::connect("127.0.0.1", 8080).unwrap();
     socket.write(bytes!("GET / HTTP/1.0\n\n"));
     let response = socket.read_to_end();
     ```
@@ -99,11 +97,9 @@ Some examples of obvious things you might want to do
     # fn foo() {
     # #![allow(dead_code)]
     use std::io::{TcpListener, TcpStream};
-    use std::io::net::ip::{Ipv4Addr, SocketAddr};
     use std::io::{Acceptor, Listener};
 
-    let addr = SocketAddr { ip: Ipv4Addr(127, 0, 0, 1), port: 80 };
-    let listener = TcpListener::bind(addr);
+    let listener = TcpListener::bind("127.0.0.1", 80);
 
     // bind the listener to the specified address
     let mut acceptor = listener.listen();