totem: Add Kronosnet transport.

This is a big update that removes RRP & MRP from the codebase
and makes knet the default transport for corosync. UDP & UDPU
are still (currently) supported but are deprecated. Also crypto
and mutiple interfaces are only supported over knet.

To compile this codebase you will need to install libknet from
https://github.com/fabbione/kronosnet

The corosync.conf(5) man page has been updated with info on the new
options. Older config files should still work but many options
have changed because of the knet implementation so configs should
be checked carefully. In particular any cluster using using RRP
over UDP or UDPU will not start as RRP is no longer present. If you
need multiple interface support then you should be using the knet transport.

Knet brings many benefits to the corosync codebase, it provides support
for more interfaces than RRP (up to 8), will be more reliable in the event
of network outages and allows dynamic reconfiguration of interfaces.
It also fixes the ifup/ifdown and 127.0.0.1 binding problems that have
plagued corosync/openais from day 1

Signed-off-by: Christine Caulfield <ccaulfie@redhat.com>