Add base implementation of extendable events classes

Modified server deletion to use internal event handlers from the
Eloquent models themselves. Also added a few preliminary event handlers
in the `Pterodactyl\Events\<USer|Server> namespace that users can hook
into in EventServiceProvider to perform their own actions as they
please (such as push notifications and such).

app/Listeners/DeleteServerListener.php

@@ -1,62 +0,0 @@
-<?php
-/**
- * Pterodactyl - Panel
- * Copyright (c) 2015 - 2017 Dane Everitt <dane@daneeveritt.com>.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-namespace Pterodactyl\Listeners;
-
-use Carbon;
-use Pterodactyl\Jobs\DeleteServer;
-use Pterodactyl\Jobs\SuspendServer;
-use Pterodactyl\Events\ServerDeleted;
-use Illuminate\Foundation\Bus\DispatchesJobs;
-
-class DeleteServerListener
-{
-    use DispatchesJobs;
-
-    /**
-     * Create the event listener.
-     *
-     * @return void
-     */
-    public function __construct()
-    {
-        //
-    }
-
-    /**
-     * Handle the event.
-     *
-     * @param  DeleteServerEvent  $event
-     * @return void
-     */
-    public function handle(ServerDeleted $event)
-    {
-        $this->dispatch((new SuspendServer($event->server))->onQueue(env('QUEUE_HIGH', 'high')));
-        $this->dispatch(
-            (new DeleteServer($event->server))
-            ->delay(Carbon::now()->addMinutes(env('APP_DELETE_MINUTES', 10)))
-            ->onQueue(env('QUEUE_STANDARD', 'standard'))
-        );
-    }
-}