yast2-add-on from YaST:Head:installer project

对于 openSUSE 13.1，请以根用户 root 运行下面命令：

zypper addrepo https://download.opensuse.org/repositories/YaST:Head:installer/openSUSE_13.1/YaST:Head:installer.repo
zypper refresh
zypper install yast2-add-on