Some fixes to get along with the new bootstrapping

src/Core/DatabaseServiceProvider.php

@@ -0,0 +1,46 @@
+<?php namespace Flarum\Core;
+
+use Flarum\Core;
+use Flarum\Support\ServiceProvider;
+use Illuminate\Database\ConnectionResolver;
+use Illuminate\Database\Connectors\ConnectionFactory;
+use Illuminate\Database\Eloquent\Model;
+use PDO;
+
+class DatabaseServiceProvider extends ServiceProvider
+{
+    /**
+     * Register the service provider.
+     *
+     * @return void
+     */
+    public function register()
+    {
+        $this->app->singleton('flarum.db', function () {
+            $factory = new ConnectionFactory($this->app);
+            $connection = $factory->make($this->app->make('flarum.config')['database']);
+            $connection->setEventDispatcher($this->app->make('Illuminate\Contracts\Events\Dispatcher'));
+            $connection->setFetchMode(PDO::FETCH_CLASS);
+            return $connection;
+        });
+
+        $this->app->alias('flarum.db', 'Illuminate\Database\ConnectionInterface');
+
+        $this->app->singleton('Illuminate\Database\ConnectionResolverInterface', function () {
+            $resolver = new ConnectionResolver([
+                'flarum' => $this->app->make('flarum.db'),
+            ]);
+            $resolver->setDefaultConnection('flarum');
+            return $resolver;
+        });
+
+        $this->app->alias('Illuminate\Database\ConnectionResolverInterface', 'db');
+
+        if (Core::isInstalled()) {
+            $this->app->booting(function() {
+                $resolver = $this->app->make('Illuminate\Database\ConnectionResolverInterface');
+                Model::setConnectionResolver($resolver);
+            });
+        }
+    }
+}