Progress on bp:virt-driver-cleanup This series of patches converts the virt drivers to loading via importutils making it possible to add a virt driver without changing core code. It deprecates the use of connection_type in favor of a full driver name in compute_driver. Based on email thread with Vish and Jay Pipes on approaches to do this. Change-Id: I48366ec7efc7b095859988e5e6ac5a853b98b8a7