Added chmod perm, modal to change, api with local/ftp/sftp (#399)

Read a fill current permissions for local driver

Finished permissions for ftp driver, read and change

Read permissions for sftp adapter

Created FilegatorFtp for a cleaner permissions integration

Implemented recursive chmod options for files/folders

Modified tests to cover permissions

Lint frontend permissions component

backend/Services/Storage/Adapters/FilegatorFtp.php

@@ -0,0 +1,91 @@
+<?php
+
+/*
+ * This file is part of the FileGator package.
+ *
+ * (c) Milos Stojanovic <alcalbg@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE file
+ */
+
+namespace Filegator\Services\Storage\Adapters;
+
+use League\Flysystem\Adapter\Ftp;
+use League\Flysystem\NotSupportedException;
+
+class FilegatorFtp extends Ftp
+{
+
+    /**
+     * Normalize a file entry.
+     *
+     * @param string $item
+     * @param string $base
+     *
+     * @return array normalized file array
+     *
+     * @throws NotSupportedException
+     */
+    protected function normalizeObject($item, $base)
+    {
+        $systemType = $this->systemType ?: $this->detectSystemType($item);
+
+        if ($systemType === 'unix') {
+            $result = $this->normalizeUnixObject($item, $base);
+            return $this->afterNormalizeUnixObject($result, $item, $base);
+        } elseif ($systemType === 'windows') {
+            $result = $this->normalizeWindowsObject($item, $base);
+            return $this->afterNormalizeWindowsObject($result, $item, $base);
+        }
+
+        throw NotSupportedException::forFtpSystemType($systemType);
+    }
+
+    /**
+     * Normalize a Unix file entry, with permissions.
+     *
+     * Given $item contains:
+     *    '-rw-r--r--   1 ftp      ftp           409 Aug 19 09:01 file1.txt'
+     *
+     * This function will return:
+     * [
+     *   'type' => 'file',
+     *   'path' => 'file1.txt',
+     *   'visibility' => 'public',
+     *   'size' => 409,
+     *   'timestamp' => 1566205260,
+     *   'permissions' => 644
+     * ]
+     *
+     * @param array $result original normalized file array
+     * @param string $item
+     * @param string $base
+     *
+     * @return array normalized file array
+     */
+    protected function afterNormalizeUnixObject($result, $item, $base)
+    {
+        $item = preg_replace('#\s+#', ' ', trim($item), 7);
+        list($permissions, /* $number */, /* $owner */, /* $group */, $size, $month, $day, $timeOrYear, $name) = explode(' ', $item, 9);
+        $permissions = $this->normalizePermissions($permissions);
+
+        $result['permissions'] = decoct($permissions);
+        return $result;
+    }
+
+    /**
+     * Normalize a Windows/DOS file entry, with permissions.
+     *
+     * @param array $result original normalized file array
+     * @param string $item
+     * @param string $base
+     *
+     * @return array normalized file array
+     */
+    protected function afterNormalizeWindowsObject($result, $item, $base)
+    {
+        $result['permissions'] = 777;
+        return $result;
+    }
+
+}