====== crawlingRetweet(retweet_url, weibo_id) ======
===== Description =====
Extract retweet of original weibo post and insert to database.
===== Parameters =====
^  Parameter  ^  Necessity  ^  Type  ^  Description  ^
|  retweet_url  |  required  |  string  |  the retweet link url of original weibo  |
|  weibo_id  |  required  |  string  |  original weibo id  |

===== Output =====
^ Parameters ^ Type ^ Description ^
| status | string | show the crawler running status |

===== Implementation =====
  - masterStart(). Create multiple processes to begin crawling data.
  - wapLogIn(). Log in sina Account.
  - weiBoWapSearch(searchStr, Sid). Use searchStr(person name or company name) and search id(person id or company id) to search related weibo
    * extractTopic(person_name or company_name, person_id or company_id). Extract weibo text and insert to database.
    * getRetweet(retweet_url, weibo_id). Extract retweet of original weibo text and insert to database.

===== Related Work =====
None
===== Issues About The Crawler =====
  - Sina Weibo API is not not so effective, it need to be authorized but the crawler would not pass sina's examine and verify. 
  - Using browser’s cookies to log in sina account.
  - Using the url weibo.cn instead of www.weibo.com to crawl data, because the latter one’s tweet data is sealed in javascript and it’s difficult to extract.
  - Using multiple proxies to prevent sina block our ip.
  - For speeding up the crawler, using multiple processes and accounts.