Picking in 3D to select module

[Daniel Lichau]

Here is attached a prototype script module allowing to select modules in the pool or tree view by picking shapes in the 3D viewer.

You can activate picking-to-select by pressing the "Pick" button or the "F3" key (loading this script object defines a procedure attached to F3).

Selection can be combined with shift and ctrl keys, yet the behavior may not be fully consistent in this preliminary version.

Also some displayed representations may not be selectable by picking (e.g. Voltex, DisplayColormap, shapes inside transform editors...)

Daniel