Fix WHQL AddressChange test

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Add receiver watchdog that will move things along if the backend fails to
send receive events. Also tighten up the transmit watchdog - 30s seems a
bit too long.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Merge pull request #15 from pauldu/master

WHQL fix and watchdog work

Approved-By: Ben Chalmers <been.chalmer@citrix.com>