AW: Official VisAD logo

Hi Doug and others,

> I like the idea of including some data representation (e.g. a globe)
> we shouldn't be too specific about the type of data (e.g. met only)
> VisAD can do so much more.

I made some globes with VisAD. See them at Let me know if I should make
some more with other regions of the earth, other colors or other sizes.

Cheers, Mathias