v1.4.0

A major new feature release, see release announcement.

• Feature: Simplify usage by supporting new default loop.
  (#410 by @clue)

  // old (still supported)
  $browser = new React\Http\Browser($loop);
  $server = new React\Http\Server($loop, $handler);
  
  // new (using default loop)
  $browser = new React\Http\Browser();
  $server = new React\Http\Server($handler);