Fix some issues in filling zones normals.
Fix an issue with some models that have materials but didn't defined the diffuse color.
Workaround for Bug #1443431.
Implement some missing "code logic" for pervertexperface normals.
Remove some not used functions.
Calculate normals using double type.
wxUpdateUIEvent events can be sent to parent frames, when opening a menu in a child frame, if parent and child frame share same ID fro menuitems (or tools)
The wrong menuitem can be used in some cases ( because there are more than one menuitem with the same identifier), by a wxUpdateUIEvent event function run in a parent frame.
jean-pierre charras
unknown
Mario Luzeiro