Currently our logging in processing is very inconsistent:
some log strings mention node UUID, some - node BMC IP, some nothing.
This change introduces a common prefix for all processing logs
based on as much information as possible.
Only code that actually have some context about the node (either
NodeInfo or introspection data) is updated.
Also logging BMC addresses can be disabled now.
Updates example.conf (a lot of updated comments from oslo).
Change-Id: Ib20f2acdc60bfaceed7a33467557b92857c32798