Add barrier block, invisible yet obstacle, for https://github.com/satoshinm/WebSandboxMC/issues/55
Add barrier block, invisible yet obstacle, for https://github.com/satoshinm/WebSandboxMC/issues/55

satoshinm/NetCraft,satoshinm/NetCraft,satoshinm/NetCraft,satoshinm/NetCraft,satoshinm/NetCraft