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 reactphp#405 and partially on reactphp#422

Author: WyriHaximus

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:
 
@@ -2695,6 +2696,8 @@ $http = new React\Http\HttpServer(
 ```
 > Internally, this class is used as a "value object" to override the default timeout of one minute.
   As such it doesn't have any behavior internally, that is all in the internal "StreamingServer". 
+  This timeout is only in effect if we expect data from the client, not when we are writing data to
+  the client.
 
 #### StreamingRequestMiddleware
 

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);