Each routing protocol has its own metric and private
variables, therefore it is useful to introduce a new API
for originator information printing.

This API needs to be implemented by each protocol in order
to provide its specific originator table output.
Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>