* serious code cleanup (remove duplicate code)
* shows (option in 3D preference menu) the copper items (tracks, zones...) in 3D, using 35 microns copper thickness.
However, because there are a lot more3D data to show (roughly 4 times more), this is slower.
All: press ctrl+shift key when moving the mouse allows the graphic cursor to be moved outside the grid.
(useful to place graphic objects, texts in any position, regardless the current grid)