FEATURE #1337: add file upload

This commit registers new items into admin menu and adds functionality for uploading files.

resources/lang/en/admin/fileManager.php

@@ -0,0 +1,11 @@
+<?php
+return [
+    'upload'            => 'Upload new file',
+    'newFile'           => 'New file',
+    'invalidFile'       => 'The file you submitted is somehow not valid file!',
+    'noFileSpecified'   => 'You have not specified any file for upload',
+    'uploadSuccessfull' => 'Your file was successfully uploaded',
+    'selectFile'        => 'Select file for upload',
+    'keywords'          => 'Keywords (comma separated)',
+    'description'       => 'File description'
+];

resources/lang/en/admin/mainMenu.php

@@ -8,6 +8,10 @@ return [
     'userDetail'           => 'Detail',
     'customFields'         => 'Custom fields',
     'customFieldsOverview' => 'Overview',
-    'customFieldsNew' => 'New field',
-    'settings'             => 'Settings'
+    'customFieldsNew'      => 'New field',
+    'settings'             => 'Settings',
+    'fileManager'          => 'File manager',
+    'uploadFile'           => 'New file',
+    'uploadImage'          => 'New image',
+    'uploadedFiles'        => 'Overview'
 ];