This makes me pleased... ;D
Here is that code modified to run on an arduino with the doubles changed to floats and some other things changed. If you want to track the sun then you simply don't need that degree of accuracy. I also removed the seconds value in my code as it was unnecessary for most uses but you could add it back in.
http://www.mowcius.co.uk/suntrackercode.html
The code is also stuck all in one sketch rather than the library as I was having some funny problems with it so I gave up and made it into a single sketch.
Mowcius