tools/libxendevicemodel: introduce the new library

tools/libxendevicemodel: introduce the new library

The new xendevicemodel library is intended to be used by all Xen device
models such that the only hypercall that use will be the dm_op hypercall
added by commit 524a98c2.

This patch adds the boilerplate for the new library, with only open() and
close() entry points, and calls to those from libxenctrl in preparation
for the compat layer added by a subsequent patch.

[ Also: update MINIOS_UPSTREAM_REVISION and QEMU_TRADITIONAL_REVISION
  to the commits with the corresponding changes to those other trees
  - Ian Jackson ]

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>