Etienne 3d objs

- meta for 'scatter3d', 'surface', 'scene', 'zaxis', and 'error-z', 
I haven't played with it myself... so the options are correct as they are, and this is either how it SHOULD work or how it ALREADY DOES work ( @bpostlethwaite confirm?)

Text should be positioned in screen-space, not in data-space - meaning that if you put it to the right it will always be to the right, regardless of how you rotate the scene, so textposition needs no concept of depth or a 3rd dimension.