rename for new graph
introduce new graph to AllPairShortestPath
introduce new graph to SingleSourceShortestPathAlgorithm
introduce new graph to MaximumFlowAlgorithm
introduce new graph to MinimumSpanningTreeAlgorithm
introduce new graph to RootedTree
introduce new graph to NegativeCycleFinder
introduce new graph to DirectedGraphFromUndirected
simple rename
refactoring not to use old graph
rename MutableUndirectedGraph -> MutableUndirectedUnweightedGraph