[crossfire] Compiling gridarta with ant

[Kevin R. Bulgrien]

> > Resolved by adding another package, though I did not know how to figure out
> > which "optional task" package to get, so I just kept trying different
> > ones... There must be a better way.
> 
> I had some issues under Gentoo, too, related to optional packages. I think I 
> needed to add "ant-tasks" to make it compile.
> 
> Thanks for the tests, and of course feel free to update documentation(s) when 
> needed :)
> 
> Nicolas

I'm not on the gridarta developer list, so I posted the information here so that
someone could add what they wanted to add.  I already put a document in
the crossfire project...