[luatex] ifluatex update

[Heiko Oberdiek]

On Wed, Apr 08, 2009 at 11:04:35AM +0200, Elie Roux wrote:

> I think ifluatex needs an update,

And others of my packages (ifpdf, ...)

> to test directlua instead of 
> luatexversion isn't it? Heiko can you do it please?

Checking the existence of \directlua is useless, because the user
don't know, how to call it, if \luatexversion isn't available.
Thus I must at least provide \luatexversion.
(tex.enableprimitives might fail, even if \luatexversion
had the meaning "undefined" before, see dev-luatex).

Yours sincerely
  Heiko <oberdiek at uni-freiburg.de>