Two new informative CLI commands for OSPF.

Two new informative CLI commands for OSPF.

Two new CLI commands for OSPF giving nice informative (and still machine
parsable) representation of OSPF network graph (based on datas from the
LSA database).

The first command (show ospf topology) shows routers, networks and stub
networks, The second command (show ospf state) shows also external
routes and area-external networks and routers propagated by given area
boundary router.