[GRASS5] New gui.tcl generic user interface

[Glynn Clements]

Hamish wrote:

> > I'd add the integration of NVIZ and 2D displays as another important
> > goal for the raster side.
> 
> I'm still not convinced that this should be attempted.
> OpenGL canvasses aside,

There's no need to leave them aside. The fact that NVIZ requires
OpenGL is more than enough reason to keep it separate.

In several regards, OpenGL is an extremely "expensive" dependency, and
should only be used by applications which can't do anything useful
without it.

-- 
Glynn Clements <glynn at gclements.plus.com>