Ensure network interfaces are in requested order

_build_network_info_model was iterating current_neutron_ports
instead of port_ids which contains ports in their correctly requested
order. Because of this the requested nic order was no longer being
perserved. This patch fixes this and also changes the order of ports
in test_build_network_info_model() so this case is tested.

Change-Id: Ia9e71364bca6cbc24ebc1c234e6a5af14f51cd62
Closes-bug: #1300325
(cherry picked from commit 721e7f939859fbfe6b0c79ef3a6d5e43c916da65)
mark vif_driver as deprecated and log warning

Several classes were dropped from nova.virt.libvirt.vif from havana ->
icehouse, leading to invalid configurations if one of these classes was
used in the libvirt_vif_driver setting in nova.conf.  The error message
produced by nova-compute in this situation is misleading.

This patch introduces stubs for all of the classes that were removed.
These stubs inherit from LibvirtGenericVIFDriver and log a deprecation
warning in __init__.

This patch also marks the vif_driver option as deprecated.

Change-Id: I6d6cb9315ce6f3b33d17756bcdc77dccda26fefe
Closed-bug: 1302796
(cherry picked from commit 9f6070e194504cc2ca2b7f2a2aabbf91c6b81897)
Merge "mark vif_driver as deprecated and log warning" into milestone-proposed
Merge "Ensure network interfaces are in requested order" into milestone-proposed