New version of vhd-format, vhd-tool, tar-format, nbd
s/ocaml/OCaml/
nbd: add dependency on cmdliner

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Merge pull request #1321 from djs55/vhd.0.6.4

New version of vhd-format, vhd-tool, tar-format, nbd