In this paper we present an algorithm, called conauto-2.0, that can
efficiently compute a set of generators of the automorphism group of a graph,
and test whether two graphs are isomorphic, finding an isomorphism if they are.
This algorithm uses the basic individualization/refinement technique, and is an
improved version of the algorithm conauto, which has been shown to be very fast
for random graphs and several families of hard graphs.