The new selection model is not usable for the OriginFeature's view
provider due to from one side it doesn't really have any subfeatures, so
it won't be really needed, and on the other side we will have to use
SoFCSelection because in that case it isn't possible to implement
highlighting in any sane way (unless we will reimplement drawing ourselfs).
- Share the code of Gui::ViewProviderPlanes and Gui::ViewProviderLine
in Gui::ViewProviderOriginFeature
- Add support for coloring and transparencing the OriginFeatures by
ViewProviderGeometryObject means.
