Bugs fixed in kml code for Google Earth Superoverlays

I fixed a few bugs in my kml-generating code, and also uploaded the superoverlay package for Arapahoe Basin, which I had apparently forgotten somehow.

I think everything will load more smoothly now. I was having trouble getting the highest resolution tiles to load, but I fiddled with some kml parameters and that seems to have fixed that. Also, some people were getting network link errors caused by my code trying to link to more tiles than actually existed in some cases. That should be completely fixed now.