History:    2009-07-03: Added NetBoot command.     解决Finder里面隐藏系统文件的问题:   sudo /Developer/Tools/SetFile -a V /bin sudo /Developer/Tools/SetFile -a V /cores sudo /Developer/Tools/SetFile -a V /dev sudo /Developer/Tools/SetFile -P -a V /etc sudo /Developer/Tools/SetFile -a V /home sudo /Developer/Tools/SetFile -a V /mach_kernel sudo /Developer/Tools/SetFile -a V /mach_kernel.ctfsys sudo /Developer/Tools/SetFile -a V /net sudo /Developer/Tools/SetFile -a V /private sudo /Developer/Tools/SetFile -a V /sbin sudo /Developer/Tools/SetFile -P -a V /tmp sudo /Developer/Tools/SetFile -a V /usr sudo /Developer/Tools/SetFile -a V /Volumes sudo /Developer/Tools/SetFile -P -a V /var   sudo rm -f /Library/Caches/com.apple.LaunchServices*.csstore sudo reboot   设置从NetBoot服务启动：   /usr/sbin/bless --netboot --server <url or ip of server> --nextonly