recoverd: Fix tunable NoIPTakeoverOnDisabled, rename to NoIPHostOnAllDisabled

recoverd: Fix tunable NoIPTakeoverOnDisabled, rename to NoIPHostOnAllDisabled

This really needs to be per-node.  The rename is because nodes with
this tunable switched on should drop IPs if they become unhealthy (or
disabled in some other way).

* Add new flag NODE_FLAGS_NOIPHOST, only used in recovery daemon.

* Enhance set_ipflags_internal() and set_ipflags() to setup
  NODE_FLAGS_NOIPHOST depending on setting of NoIPHostOnAllDisabled
  and/or whether nodes are disabled/inactive.

* Replace can_node_servce_ip() with functions can_node_host_ip() and
  can_node_takeover_ip().  These functions are the only ones that need
  to look at NODE_FLAGS_NOIPTAKEOVER and NODE_FLAGS_NOIPHOST.  They
  can make the decision without looking at any other flags due to
  previous setup.

* Remove explicit flag checking in IP allocation functions (including
  unassign_unsuitable_ips()) and just call can_node_host_ip() and
  can_node_takeover_ip() as appropriate.

* Update test code to handle CTDB_SET_NoIPHostOnAllDisabled.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Pair-programmed-with: Amitay Isaacs <amitay@gmail.com>