Wrong recognition of binary relations in multi-relational networks

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In multi-relational networks where one relation is weighted/valued, the program interprets all relations as valued and uses Dijkstra algorithm for distances/indices computation. This is usually not a problem, since it correctly computes the distances and centralities. But there might be cases when this poses a problem. After all, it makes no sense to work on a binary relationship and have the program ask you every now and then what to do with the edge weights... This is related to #53