Add packages from 'upstream' xen-dist-ocaml.hg

These will form the base of our build environment for backporting new code.

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
Move to xmlm 1.1.1

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
Add vhd-tool related specs into staging area