Introduce xml_node_new_element_unique(name, parent, cdata)

This function ensures that a child element named @name exists and
sets its cdata to @cdata.

It can be used to replace code like this:

	if (!(e = xml_node_get_child(node, "state")))
		e = xml_node_new("state", node);
	xml_node_set_cdata(e, opt_state);

with

	e = xml_node_new_element_unique("state", opt_state, node);

Signed-off-by: Olaf Kirch <okir@suse.de>
Change do_lease() to use new xml_new_element_unique fctn

Signed-off-by: Olaf Kirch <okir@suse.de>
Add missing ni_objectmodel_init call in wicked lease install

Signed-off-by: Olaf Kirch <okir@suse.de>
Prevent ni_leaseinfo_dump from complaining about lease types it doesn't know

This includes INTRINSIC as well as AUTOCONF

Signed-off-by: Olaf Kirch <okir@suse.de>
schema/constants.xml: add a new enum type for address family, named builtin-address-family

Signed-off-by: Olaf Kirch <okir@suse.de>
All system updates from an intrinsic lease were ignored, because ni_config_addrconf_update_mask() returned a mask of 0 for this type

Signed-off-by: Olaf Kirch <okir@suse.de>
Change the installLease code to put the lease request one level down, and pass along type/family

Signed-off-by: Olaf Kirch <okir@suse.de>
ni_objectmodel_netif_install_lease: assume that the new lease should update everything it can

Signed-off-by: Olaf Kirch <okir@suse.de>
Major rewrite of client side lease code, in order to support PPP's ip-up and ip-down scripts

This also includes support for resolver information.

Signed-off-by: Olaf Kirch <okir@suse.de>
Actually fix examples in the comment preceding do_lease()

Signed-off-by: Olaf Kirch <okir@suse.de>
Merge pull request #398 from okirch/intrinsic-leases