多版本firefox共存

https://blog.csdn.net/gavinxlf/article/details/53173034
https://blog.csdn.net/weixin_33979745/article/details/90100332
https://blog.csdn.net/czmchen/article/details/81075486
http://mozilla.com.cn/thread-21647-1-1.html
http://mozilla.com.cn/forum.php?mod=viewthread&tid=21637
http://www.51testing.com/html/74/22274-204723.html