Remove IP helper linkage (and hence dependency on netio.sys)

The linkage dependency on netio.sys prevents SDV from working. Since we need
the IP helper functionality there's no choice other than to remove the
linkage and replace it with run-time function lookup. Alas this is not as
simple as using MmGetSystemRoutineAddress() as that only works for kernel and
hal functions. We need to actually parse the netio.sys module export table
directly and then create thunks to jump into the code.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Add SDV to normal driver build

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Merge pull request #24 from pauldu/netio

Get SDV working