Warning when following tutorial

[Stan Shebs]

Erik Sigra wrote:
> 
> Hi,
> I tried to follow the game design manual tutorial. When starting the
> game, I get the following warning:
> 
> Warning: g-vs-t:12 The terrain type form has no property named color
> Xconq may not be able to give you exactly the game that you asked for.
> Do you want to continue setting up this game?
> 
> g-vs-t:12 is:
> (terrain-type street (color "gray"))
> 
> What is wrong?

The tutorial is out-of-date - the "color" property was dropped a
while back, because it became redundant with "image-name" (colors
were converted into 1x1 images).  Just use "image-name" instead.

I fixed the tutorial in July, after the release of 7.3 (clever
timing, huh), so you can pick up the more accurate version from CVS.

Stan