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

Merge branch 'auto_concurrency_limiter' of ssh://github.com/TousakaRin/brpc into auto_concurrency_limiter

Add document link

Auto concurrency limiter