order_edges.cpp

		SelectSubsetElements<Vertex>(sel, sh, si, true);
		std::vector<Vertex*> vrts;
		vrts.assign(sel.vertices_begin(), sel.vertices_end());
		sel.clear();

		std::vector<Edge*> edges;
		SelectSubsetElements<Edge>(sel, sh, si, true);
		edges.assign(sel.edges_begin(), sel.edges_end());
		sel.clear();

		vrts.push_back(edges[0]->vertex(0));
		vrts.push_back(edges[0]->vertex(1));
		Vertex* prevVertex = edges[0]->vertex(1);
		size_t numIterations = edges.size()-1;
		edges.erase(edges.begin());
		for (size_t j = 0; j < numIterations; j++) {
			for (size_t i = 0; i < edges.size(); i++) {
				Edge* nextEdge = edges[i];
				if (nextEdge->vertex(0) == prevVertex) {
					vrts.push_back(nextEdge->vertex(1));
					prevVertex = nextEdge->vertex(1);
					edges.erase(edges.begin()+i);
					break;
				}
				if (nextEdge->vertex(1) == prevVertex) {
					vrts.push_back(nextEdge->vertex(0));
					prevVertex = nextEdge->vertex(0);
					edges.erase(edges.begin()+i);
					break;
				}
			}
		}