Close inactive connections and requests

This new middleware introduces a timeout of closing inactive
connections between requests after a configured amount of seconds.

This builds on top of #405 and partially on #422

README.md

@@ -2683,7 +2683,8 @@ access its underlying response object.
 #### InactiveConnectionTimeoutMiddleware
 
 The `React\Http\Middleware\InactiveConnectionTimeoutMiddleware` is purely a configuration middleware to configure the
-`HttpServer` to close any inactive connections between requests to close the connection and not leave them needlessly open.
+`HttpServer` to close any inactive connections between requests to close the connection and not leave them needlessly 
+open. The default is `60` seconds of inactivity and should only be changed if you know what you are doing.
 
 The following example configures the `HttpServer` to close any inactive connections after one and a half second:
 

src/Io/StreamingServer.php

@@ -418,7 +418,11 @@ public function parseRequest(ConnectionInterface $connection)
         };
         $connection->once('close', $closeTimerCanceler);
         $connection->once('data', $dataTimerCanceler);
-        $removeTimerHandler = function () use ($parser, $connection, $closeTimerCanceler, $dataTimerCanceler, &$removeTimerHandler) {
+        $removeTimerHandler = function ($_, $conn) use ($parser, $connection, $closeTimerCanceler, $dataTimerCanceler, &$removeTimerHandler) {
+            if (\spl_object_hash($conn) !== \spl_object_hash($connection)) {
+                return;
+            }
+
             $connection->removeListener('close', $closeTimerCanceler);
             $connection->removeListener('data', $dataTimerCanceler);
             $parser->removeListener('headers', $removeTimerHandler);