datapath-windows: Stateless TCP Tunnelling protocol - Initial implementation

datapath-windows: Stateless TCP Tunnelling protocol - Initial implementation

This change include an initial implementable of STT.

The following should be added:
[1] Checksum offload (SW and HW)
[2] LSO (SW and HW)
[3] IP layer WFP callout for IP segments

Added support for multiple (per TCP port) STT ports

Testing: link layer connection through ping works. File transfer.

Signed-off-by: Eitan Eliahu <eliahue@vmware.com>
Co-authored-by: Saurabh Shah <ssaurabh@vmware.com>
Signed-off-by: Saurabh Shah <ssaurabh@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>