datapath-windows: Add netlink command vport delete

datapath-windows: Add netlink command vport delete

Deletion of a vport is now handled both by the netlink command vport
delete and the hyper-v switch port delete handler. If a netlink
command vport delete is requested on a vport that has no hyper-v
switch port counterpart (i.e., it is a tunnel port, or or the hyper-v
switch virtual nic is disconnected), the vport is deleted and removed.

If the hyper-v switch port delete is requested (i.e. the VNic is
disconnecting) and the ovs (datapath) part is deleted (i.e. was
deleted by netlink command vport delete, or was never created by
an netlink command vport new), then the hyper-v switch port delete
function handler deletes and removes the vport.

If the hyper-v switch port delete is requested while its datapath
counterpart is still alive, or, when the netlink command vport delete
is requested while the hyper-v switch port is still alive, the port
is only marked that it's part is deleted - the field hvDeleted was
added to OVS_VPORT_ENTRY to specify if the hyper-v switch port side
was deleted; if the ovs (datapath) port number is invalid, then it
means that the ovs (datapath) side of the port is deleted (or, not
created).

Signed-off-by: Samuel Ghinet <sghinet@cloudbasesolutions.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Acked-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Eitan Eliahu <eliahue@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Tested-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>