Update ImageFormat enum to include VHDX format introduced with Hyper-V
Server 2012.
Remove existing Hyper-V plugin, because it does not work and is dead
code.
Remove references to existing Hyper-V plugin from config files.
Remove Hypervisor.HypervisorType.Hyperv special cases from manager code
that are unused or unsupported.
Specifically, there is no CIFS secondary storage class
"CifsSecondaryStorageResource". Also, the Hyper-V plugin's
ServerResource is contacted by the management server and not the other
way around.
Add Hyperv-V support to ListHypervisorsCmd API call
Signed-off-by: Edison Su <sudison@gmail.com>