Add variables and defaults for multiple types of ip addresses.

Each node can have 3 IPs.
1. ansible_default_ip4 - whatever ansible things is the first IPv4 address
   usually with the default gw.
2. ip - An address to use on the local node to bind listeners and do local
   communication.  For example, Vagrant boxes have a first address that is the
   NAT bridge and is common for all nodes.  The second address/interface should
   be used.
3. access_ip - An address to use for node-to-node access.  This is assumed to
   be used by other nodes to access the node and may not be actually assigned
   on the node.  For example, AWS public ip that is not assigned to node.

This updates the places addresses are used to use either ip or access_ip and walk
up the list to find an address.