[GRASS5] Re: new GIS Manager icons

Minor issue:

d.nviz and xganim buttons from a new d.m window with no map layers
causes errors in the terminal window. Needs a test at the start of the
script(s). Add a test for xganim existance as it isn't always built.

I agree pan, zoom buttons are slightly huge now.

Show vector columns to xterm with background color of d.m is very nice
in practice.

Hamish