Add ocaml-sha v1.9

Signed-off-by: John Else <john.else@citrix.com>
Add ocaml-sha patch to remove O_CLOEXEC

Signed-off-by: John Else <john.else@citrix.com>
Add ocaml-tar 0.2.0

Signed-off-by: John Else <john.else@citrix.com>
Update to stdext 0.10.0

Signed-off-by: John Else <john.else@citrix.com>
Update to nbd 1.0.2

Signed-off-by: John Else <john.else@citrix.com>
Patch nbd to not install nbd-tool

Signed-off-by: John Else <john.else@citrix.com>
Update to vhd-tool 0.7.2

Signed-off-by: John Else <john.else@citrix.com>