improve RRP support and use 'name' subkey as default

improve RRP support and use 'name' subkey as default

This patches allows to configure RRP (= redundant ring protocol)
at cluster creation time. Also setting ring 0 and 1 addresses when
adding a new node. This helps and fixes some bugs when corosync runs
completely separated on an own network.
Changing rrp configs, or the bindnet addresses automatically on an
running cluster isn't supported and not planned, as it needs an
complete cluster reboot and has to many possible failure points.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>