Remove some deprecated functions.

app/Support/Twig/Extension/Account.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * Account.php
+ * Copyright (c) 2018 thegrumpydictator@gmail.com
+ *
+ * This file is part of Firefly III.
+ *
+ * Firefly III is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Firefly III is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Firefly III. If not, see <http://www.gnu.org/licenses/>.
+ */
+declare(strict_types=1);
+
+namespace FireflyIII\Support\Twig\Extension;
+
+use FireflyIII\Models\Account as AccountModel;
+use FireflyIII\Repositories\Account\AccountRepositoryInterface;
+use Twig_Extension;
+
+/**
+ * Class Account.
+ */
+class Account extends Twig_Extension
+{
+    /**
+     * @param AccountModel $account
+     * @param string       $field
+     *
+     * @return string
+     */
+    public function getMetaField(AccountModel $account, string $field): string
+    {
+        /** @var AccountRepositoryInterface $repository */
+        $repository = app(AccountRepositoryInterface::class);
+        $result     = $repository->getMetaValue($account, $field);
+        if (null === $result) {
+            return '';
+        }
+
+        return $result;
+    }
+}