当clone github时若连接不上，可以使用http代理，形如：export http_proxy=61.172.249.94:80
一年成为emacs高手: https://github.com/redguardtoo/mastering-emacs-in-one-year-guide
http://www.sanityinc.com/
别人的emacs配置：
陈刚的 https://github.com/redguardtoo/emacs.d
https://github.com/xiaohanyu/oh-my-emacs
https://github.com/magnars/.emacs.d
https://github.com/eschulte/emacs-starter-kit/
https://github.com/bbatsov/prelude
https://github.com/purcell/emacs.d