Shortcut for making map-style images (perhaps include with FITS style?)

[drzowie]

Arbitrary-grid images and other sorts of contouring require splot (i.e. 3-d mode) with the "set view map" shortcut. We should have a way to set that up simply. Question - should it be mocked up as a pseudo-2D mode for interface purposes? Or should we take the lazy way out (as did the gnuplot developers) and treat it as a real 3-D mode that happens to be looking straight down?