[freebsd91p7][git] pick up [cygwin] commit manually to fix prompt error.

commit 47ec70dd81563dd54212f147ce9af63ec1cb4afc
Author: starleoda <starleoda@gmail.com>
Date:   Sat Oct 26 02:53:33 2013 +0800

    [cygwin][git] Hide error msg while there is no git in current (and
    parent) folder.