修改piggydb的模版，添加备案信息

根据piggydb的github里的changelog描述，发现下面这段描述：
== Changes in version 6.14 (2013-09-01) == #v6.14

 * Added a button to expand sub-fragments at the bottom of the fragment content
 * Added support for non-ascii file names

经过在commit history里的查找，找到[https://github.com/marubinotto/Piggydb/commit/48078c1e6a39f0f196ff8b80b5ca8f0ad0161c7d commit 48078c1]号commit有实现底部添加可交互按钮的功能。
据此可以依葫芦画瓢，在底部实现一个常驻footer，放置备案信息。