router_add_to_routerlist() is supposed to be a nice minimal function
that only touches the routerlist structures, but it included a call to
dirserv_single_reachability_test().
We have a function that gets called _after_ adding descriptors
successfully: routerlist_descriptors_added. This patch moves the
responsibility for testing there.
Because the decision of whether to test or not depends on whether
there was an old routerinfo for this router or not, we have to first
detect whether we _will_ want to run the tests if the router is added.
We make this the job of
routers_update_status_from_consensus_networkstatus().
Finally, this patch makes the code notice if a router is going from
hibernating to non-hibernating, and if so causes a reachability test
to get launched.
