Streaming requests

[thekid]

This adds a new API to stream requests:

use peer\http\HttpConnection;
use peer\http\HttpRequest;
use util\cmd\Console;

$data= 'var1=1&var2=2';

$conn= new HttpConnection('http://localhost:8080/target');

$req= $conn->create(new HttpRequest());
$req->setMethod('POST');
$req->setHeader('Content-Type', 'application/x-www-form-urlencoded');
$req->setHeader('Content-Length', strlen($data));
$req->setHeader('X-User-Id', 6100);

$transfer= $conn->open($req);
$transfer->write($data);
$res= $conn->finish($transfer);

Console::writeLine($res);