libslang2 from home:urbic project

对于 openSUSE Tumbleweed，请以根用户 root 运行下面命令：

zypper addrepo https://download.opensuse.org/repositories/home:urbic/openSUSE_Tumbleweed/home:urbic.repo
zypper refresh
zypper install libslang2

对于 16.0，请以根用户 root 运行下面命令：

zypper addrepo https://download.opensuse.org/repositories/home:urbic/16.0/home:urbic.repo
zypper refresh
zypper install libslang2

对于 15.6，请以根用户 root 运行下面命令：

zypper addrepo https://download.opensuse.org/repositories/home:urbic/15.6/home:urbic.repo
zypper refresh
zypper install libslang2