Better peer identification

Just for review. I will not be merging these changes into my master branch.
The peerinfo->port used to store the port on which glusterd was listening. This was required very long back, during glusterds initial development, when glusterd could listen on user defined ports. But that support has been removed since a long time, (I doubt if it even made it into a release), and this port value is useless now. When 0, the default port of 24007 is used.