Auto concurrency limiter

 change the backlog of listen() from INT_MAX to 65535

change the backlog of listen() from INT_MAX to 65535 due to the reason described in https://codereview.appspot.com/7480046/

update brpc to gydong/brpc

Make escaping and quoting in redis more reasonable

1.Flush previous component when beginning and ending quotes; 2.Escape quote symbols in quoted contents; 3.Quote backslash and doublequote when printing redis messages; 4.Print better logs for unmatched quotes

* Fix cmake build issue when use this project as a submodule.
* Add ignore.

- fix typo in server.md

Add doc for Auto concurrency limiter

Polish cl code