Add Poky Spider

Crawl http://www.seu.edu.cn
Store links in mongodb

Store document's url, links, text and body into mongodb.
Add indexer.

Parse the text, get tf-idf, build inverted table,  store in database.
Add pagerank

Store pagerank into database.
Finish basic query result page.

Finish query result page, add cache page.
Add cosine similarity to query. Combine PageRank.

Use cosine similarity to analysis query result.
Add weight for cosine similarity and PageRank.