getDB(), getRootDB()를 autoload 클래스로 변경

- 각각 DB::db(), RootDB::db()임.

d_setting/KakaoKey.orig.php

@@ -0,0 +1,8 @@
+<?php
+namespace kakao;
+
+class KakaoKey{
+    const REST_KEY = '_tK_REST_API_KEY_';
+    const ADMIN_KEY = '_tK_ADMIN_KEY_';
+    const REDIRECT_URI = '_tK_REDIRECT_URI_';
+}