Comment 10 for bug 1074415

The output of the result is described at #3.
list_networks is a function of quantum client class. It will have a list of networks and the related subnet ids.
and then we use these subnets ids to call client class's list_subnets to pull the subnets with that ids.
after that, cli command quantum net-list compose the subnets with networks and the have that output at #3.

another way is to change API to return subnets instead of a list of subnet ids of network in GET /networks.
But it will break compatibility.

So I prefer to the two-invocation one.