Add support for xen-4.5

Mostly this involves removing the (broken) generation-id stuff.

Signed-off-by: David Scott <dave.scott@citrix.com>
Regenerate OASIS

Signed-off-by: David Scott <dave.scott@citrix.com>
Merge pull request #56 from djs55/xen-4.5

Add support for xen-4.5