ANN: mirage-0.9.2 released

[Anil Madhavapeddy <anil@xxxxxxxxxx>]

I've just pushed a series of releases to OPAM, containing numerous fixes from 
Vincent, Balraj, Dave and myself.  The changelogs are below:

Mirage-Platform: https://github.com/mirage/mirage-platform/releases/v0.9.2
* [xen] Add Netif test to wait for a fixed number of ring slots > 0
* [xen] Add Evtchn.close to Xen backend.
* [xen] Disable tree-loop-distribute-patterns to workaround crash with
  gcc-4.8.  Temporary fix until we isolate the bug.
* [xen] Improved the interface of Io_page, implement some missing bits
  in Gnt.
* [xen] Several modules now have an interface similar to the one in
  the libxc bindings for OCaml. This makes it possible to write one
  application that can be compiled for the UNIX or the Xen backend.

Mirage-FS: https://github.com/mirage/mirage-fs/releases/v0.6.0
* Adapt output to mirage-platform-0.9.2 Io_page API.

Mirage-Net: https://github.com/mirage/mirage-net/releases/v0.9.2
* Improve TCP state machine for connection teardown.
* Limit fragment number to 8, and coalesce buffers if it goes higher.
* Adapt to mirage-platform-0.9.2 API changes.

Mirari: https://github.com/mirage/mirari/releases/v0.9.4
* build using ocamlbuild rather than depending on obuild.
* [xen] generate a symbol that can be used to produce stack traces with xenctx.
* mirari run --socket just runs the unikernel.
* mirari run --xen creates a xl config file and do a xl create -c unikernel.xl.

-anil