avoid the error when the /usr/local/man/man8/ not exist.
Added mod_rpi for Raspberry Pi
Merge pull request #2 from soarpenguin/master

avoid the error when the /usr/local/man/man8/ not exist.
Merge pull request #3 from kongjian/master

代码格式和注释，以及编译优化参数
Merge pull request #4 from hugozhu/master

Added mod_rpi for Raspberry Pi