Updated openstack/openstack
Project: openstack/nova  1947b4e1734f2e0f40e12e09198f19f3c2de75b0

libvirt: introduce new 'Host' class to manage the connection

Move all the code related to obtaining a new libvirt connection
out into a new 'Host' class. This covers the initial connection
attempt, testing of the connection, handling of connection close
events and handling of lifecycle events.

The appropriate tests are also moved out into a new HostTestCase
class

Blueprint: libvirt-driver-class-refactor
Change-Id: I64e84c4ed7b275632ef2ce3fa6e4be4c0ee8235a