Improve graph validator.  When creating community graph, do not obliterate weights when community is seen again.
Improve graph validator.  When creating community graph, do not
obliterate weights when community is seen again.

marcsugiyama/loom,marcsugiyama/loom,marcsugiyama/loom,FlowForwarding/loom,marcsugiyama/loom,FlowForwarding/loom,FlowForwarding/loom,FlowForwarding/loom