Fixed force directed layout to work on the top group. This probably broke it on subgroups. Also tweaked pipe links to handle the case when there is no bandwidth data (empty pipes)
Fixed force directed layout to work on the top group. This probably broke it on subgroups. Also tweaked pipe links to handle the case when there is no bandwidth data (empty pipes)

oughton/NetMapJs,oughton/NetMapJs,oughton/NetMapJs