Add Douban Plugin to PopClip

Douban is the biggest Book/Movie/Music/Event webpage in China. User could search book movie and music in Douban, and also create and join a event in Douban.

So there are some plugin for Douban.

* Douban - Search in SNS
* Douban-Book - Search book in Douban with name, isbn...
* Douban-Movie - Search movie in Douban with name, imdb...
* Douban-Music - Search music.
* Douban-Event - Search Event.

Hope this will make user easy search in Douban.