add Apache License 2.0
simplify the mongo writer
finish http://www.chinawutong.com/103.html?pid=2
finish http://wb.56888.net/OutSourceList.aspx?tendertype=4&p=1
finish http://www.51yunli.com/goods/0/0/1/0
abstract crawler.crawl()
abstract crawler.lifetime(), fixes #1
initial tornado
abstract the mongodb module
finish http://www.0256.cn/goods/?PageIndex=1
rewrite crawler_runner, now we could call the different crawler on different site
change the MongoDB.last() method, return a json list instead of a json item
Merge branch 'tornado'