Adds Hyper-V support in nova-compute (with new network_info model), including unit tests

blueprint hyper-v-revival

Features included in ths commit:

Spawn (including CoW image option support)
Destroy
Info
List
Pause
Unpause
Suspend
Resume
Reboot
Power On
Power Off
Snapshot
Volume Attach
Volume Detach
Boot from Volume
Live Migration

Supported platforms:

Windows Server / Hyper-V Server 2008 R2
Windows Server / Hyper-V Server 2012

Unit tests:

Unit tests for all the listed features are included.
Tests can be execute on Linux as well.

nova.conf relevant flags:

Compute driver:

compute_driver=nova.virt.hyperv.driver.HyperVDriver

External vswitch to be used:

vswitch_name=an_external_vswitch

Path where the VHDs are going to be stored

instances_path=C:\Hyper-V\instances

Live migration support for hosts with etherogeneus CPUs

limit_cpu_features=true

Change-Id: Ic40adcd2d78b0ca6792d77940810f5a44de8cc37

nova/tests/hyperv/stubs/README.rst

@@ -0,0 +1,2 @@
+Files with extension p.gz are compressed pickle files containing serialized
+mocks used during unit testing

nova/virt/hyperv/README.rst

@@ -0,0 +1,44 @@
+Hyper-V Volumes Management
+=============================================
+
+To enable the  volume features, the first thing that needs to be done is to
+enable the iSCSI service on the Windows compute nodes and set it to start
+automatically.
+
+sc config msiscsi start= auto
+net start msiscsi
+
+In Windows Server 2012, it's important to execute the following commands to
+prevent having the volumes being online by default:
+
+diskpart
+san policy=OfflineAll
+exit
+
+How to check if your iSCSI configuration is working properly:
+
+On your OpenStack controller:
+
+1. Create a volume with e.g. "nova volume-create 1" and note the generated
+volume id
+
+On Windows:
+
+2. iscsicli QAddTargetPortal <your_iSCSI_target>
+3. iscsicli ListTargets
+
+The output should contain the iqn related to your volume:
+iqn.2010-10.org.openstack:volume-<volume_id>
+
+How to test Boot from volume in Hyper-V from the OpenStack dashboard:
+
+1. Fist of all create a volume
+2. Get the volume ID of the created volume
+3. Upload and untar to the Cloud controller the next VHD image:
+http://dev.opennebula.org/attachments/download/482/ttylinux.vhd.gz
+4. sudo dd if=/path/to/vhdfileofstep3 
+of=/dev/nova-volumes/volume-XXXXX <- Related to the ID of step 2
+5. Launch an instance from any image (this is not important because we are
+just booting from a volume) from the dashboard, and don't forget to select
+boot from volume and select the volume created in step2. Important: Device
+name must be "vda".