git教程：http://www.runoob.com/git/git-tutorial.html
ssh key的生成：https://help.github.com/articles/generating-ssh-keys/#platform-windows
廖雪峰：http://www.liaoxuefeng.com/wiki/0013739516305929606dd18361248578c67b8067c8c017b000
原文：http://www.cnblogs.com/ieayoio/p/5151159.html