state: print error if no state has been found for given ID, this allows to find out whether transaction was ever created for given group
route: let regular route table update also get route table from nodes explicitly added via dnet_add_state() and helpers

When user (client or server) adds new nodes via dnet_add_state()
and helper functions, we put those addresses into special array.

Periodic route request thread asks for route table random X groups
plus all this addresses.

It is needed to speed up large (severl thousands of nodes) cluster
convergence - usually in such big clusters 'remote' server config option
contains the same nodes for simplicity. Thus the same nodes will always
be the first who receive information about new nodes and thus the first
to update route table, which in turn will be requested by newly connected
clients/servers.