Enable use of unencrypted cookies (#335)

Enables the use of the `cookie.unencryptedCookies` config item to specify cookies that should not be passed through the cookie encryption middleware. Cookie configuration file added in octobercms/october@ab9dcaf, documented in octobercms/docs#3644. Credit to @pikanji

src/Cookie/Middleware/EncryptCookies.php

@@ -0,0 +1,14 @@
+<?php namespace October\Rain\Cookie\Middleware;
+
+use Config;
+use Illuminate\Contracts\Encryption\Encrypter as EncrypterContract;
+
+class EncryptCookies extends \Illuminate\Cookie\Middleware\EncryptCookies
+{
+    public function __construct(EncrypterContract $encrypter)
+    {
+        parent::__construct($encrypter);
+        $except = Config::get('cookie.unencryptedCookies', []);
+        $this->disableFor($except);
+    }
+}

src/Foundation/Http/Kernel.php

@@ -51,7 +51,7 @@ class Kernel extends HttpKernel
      */
     protected $middlewareGroups = [
         'web' => [
-            \Illuminate\Cookie\Middleware\EncryptCookies::class,
+            \October\Rain\Cookie\Middleware\EncryptCookies::class,
             \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
             \Illuminate\Session\Middleware\StartSession::class,
             \Illuminate\View\Middleware\ShareErrorsFromSession::class,