ANN: mirage-0.9.3

[Anil Madhavapeddy <anil@xxxxxxxxxx>]

Great rounds of stabilization as we head for a dev preview release!  All have 
been uploaded to OPAM.  Mirari is likely to see the biggest changes as we fix 
the frontend tool to be more user-friendly.

Mirage Platform 0.9.3 (18-July-2013):
* [xen] Prevent spinning in `Activations.run` when a thread is blocked
  and then awakened.
* [xen] Gnt.grant_table_index is now an int, was an int32.
* [xen] Cleaned some C stubs files, mainly page_stubs.c
* [xen] Improved module Netif: The function create do not take a
  callback anymore, hidden some private function from the .mli.
* [unix] Add support for building and running on FreeBSD.

Mirage Net 0.9.3 (18-July-2013):
* Changes in module Manager: Removed some functions from the `.mli
  (plug/unplug) and added some modifications in the way the Manager
  interacts with the underlying module Netif. The Netif.create function
  does not take a callback anymore.

Mirari 0.9.5 (2013-07-18):
* completely remove the dependency on obuild: use ocamlbuild everywhere now.
* adapt for mirage-0.9.3 OS.Netif interfaces (abstract type `id`).
* do not output network config when there are no `ip-*` lines in the `.conf` 
file.
* do not try to install `mirage-fs` if there is no filesystem to create.
* added `nat-script.sh` to setup xenbr0 with DNS, DHCP and masqerading under 
Linux.