Don't implement path as a step

gistfile1.txt

gremlin> g.V().repeat(out()).emit().path()
==>[v[1],v[3]]
==>[v[1],v[2]]
==>[v[1],v[4]]
==>[v[1],v[4],v[5]]
==>[v[1],v[4],v[3]]
==>[v[4],v[5]]
==>[v[4],v[3]]
==>[v[6],v[3]]
gremlin> g.withSack {[]} {it.clone()} V().sack(addAll).by(fold()).repeat(out().sack(addAll).by(fold())).emit().sack()
==>[v[1],v[3]]
==>[v[1],v[2]]
==>[v[1],v[4]]
==>[v[1],v[4],v[5]]
==>[v[1],v[4],v[3]]
==>[v[4],v[5]]
==>[v[4],v[3]]
==>[v[6],v[3]]

gremlin> g.V().repeat(out()).emit().path().by("name").bytecode
==>[V(), sack("#path", add), by(name), repeat([[], [out(), sack("#path", add), by(name)]]), emit(), sack("#path")]]