FEATURE #1337: add file upload

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

app/Http/Requests/UploadRequest.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace App\Http\Requests;
+
+abstract class UploadRequest extends Request
+{
+    protected $rules = [];
+
+    abstract protected function setRules();
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array
+     */
+    public function rules()
+    {
+        // some globaly defined rules
+        $rules = [
+            'keywords' => 'max:255'
+        ];
+
+        // setup additional rules
+        $this->setRules();
+
+        foreach ($this->rules as $field => $rule) {
+            $rules[$field] = $rule;
+        }
+
+        return $rules;
+    }
+}