fix bug with flipEdgeNetwork created by piecewise Dijkstra#237

Joel-Hecht wants to merge 2 commits intonmwsharp:masternmwsharp/geometry-central:masterfrom

Joel-Hecht:fix_flipout_piecewise_dijkstraJoel-Hecht/geometry-central:fix_flipout_piecewise_dijkstraCopy head branch name to clipboard