Netif.get_writebuf now returns a Cstruct.t rather than a raw Io_page.t
Merge pull request #18 from djs55/unix-direct-cstruct

Netif.get_writebuf now returns a Cstruct.t rather than a raw Io_page.t
fix typo in CHANGES
fix compilation against latest ocaml-xenstore functor (untested apart from build)
install the packed cmx file as well as the cmxa
quieten verbosity of xen devices
fix the size of the xenstore and console rings, which should be 4096.

previously, Long_val was used, but the PAGE_SIZE macro is not an OCaml value, and so this truncated it down to 2048.
sync CHANGES
Zero the shared ring before sharing it with the driver domain

Otherwise the ring might actually contain valid request metadata
and could result in other data being transmitted unexpectedly.
Merge pull request #19 from djs55/zero-shared-ring

Zero the shared ring before sharing it with the driver domain