Define planex_version and planex_release

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Merge remote-tracking branch 'euanh/trunk-planex-update'

Signed-off-by: Jon Ludlam <jonathan.ludlam@citrix.com>

Conflicts:
	ocaml-vhd.spec.in
Merge pull request #64 from jonludlam/planex-master

Planex master