Merge pull request #8 from pauldu/master

Two fixes

Approved-By: Ben Chalmers <ben.chalmers@citrix.com>
Merge pull request #9 from pauldu/master

Find alias hardware key rather then stopping with the software key
Merge pull request #10 from pauldu/master

Fix problem of adding device without alias
Update to latest xenvif interface

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>