Added new 'species' argument to load_registry_from_db():

Arg [SPECIES]:  (optional) string
                By default, all databases that are found on the server
                and that corresponds to the correct release are probed
                for aliases etc.  For some people, depending on where
                they are in the world, this might be a slow operation.
                With the '-species' argument, one may reduce the startup
                time by restricting the set of databases that are probed
                to those of a particular species.

                Note that the latin name of the species is required,
                e.g., 'homo sapiens', 'gallus gallus', 'callithrix
                jacchus' etc.  It may be the whole species name, or only
                the first part of the name, e.g. 'homo', 'gallus', or
                'callithrix'.  This will be used in matching against the
                name of the databases.