Fixes Hyper-V agent IDE/SCSI related refactoring

Hyper-V Server 2012 R2 introduces a new feature for virtual
machines named "generation 2".

Generation 2 VMs don't support IDE devices, meaning that VHDs
and DVD Drives must be attached as SCSI, instead of IDE.

Since the Virtual Hard Disks and Virtual CD/DVD Disks can be
attached to IDE controllers or SCSI controllers (generation 2
only), some constants, variables and methods have been
improperly named, having the IDE prefix.

Partially implements: blueprint hyper-v-generation-2-vms

Change-Id: Ic281d7548dfe6b2f65290f687ea0ca694db1a4d0

Conflicts:
	nova/tests/unit/virt/hyperv/test_hypervapi.py
Hyper-V: attach volumes via SMB

Currently, the Hyper-V driver supports attaching volumes only via
iSCSI. This patch adds support for attaching volumes using VHD or
VHDX images hosted on SMB shares.

Note that the according Cinder drivers which allow exporting
images through SMB shares have been already merged.

The workflow is simple: using the connection info, the driver
chooses the right volume driver, mounts the according SMB share
using the according credentials. The only thing that needs to be
done next is actually attach the volume to an instance using its
UNC path.

Change-Id: Id5de0e6843c1035235598a4d72a00b7555187fb4
Implements: blueprint hyper-v-smbfs-volume-support

Conflicts:
	nova/tests/unit/virt/hyperv/test_hostops.py
	nova/tests/unit/virt/hyperv/test_hypervapi.py
	nova/tests/unit/virt/hyperv/test_livemigrationops.py
	nova/tests/unit/virt/hyperv/test_migrationops.py
	nova/tests/unit/virt/hyperv/test_pathutils.py
	nova/tests/unit/virt/hyperv/test_snapshotops.py
	nova/tests/unit/virt/hyperv/test_vmops.py
	nova/virt/hyperv/volumeops.py