[GRASS-dev] layer management robust

[Michael Barton]

Martin,

Your changes look nice. The slider for opacity is much easier than a  
spinctrl now that we have room for it. I just sent up (hopefully) last  
of my bug fixes too. I think the layer management in wxGUI is now  
pretty robust. It should be a lot tougher to break.

I see you've really cleaned up the display rendering module too. Once  
your nviz project is wrapped up, we might want to look into using the  
new wx.GraphicContext for compositing rather than g.pnmcomp.

Best regards
Michael