Draft: WorkingPlane, Pythonic style, improved the docstrings; added a graphic to explain the type of point that the functions return; maybe getLocalCoords() should be named getRelativeCoords(), as the return value is a relative vector referred to the plane.
Draft: WorkingPlane, Pythonic style, improved the docstrings; added a graphic to explain the type of point that the functions return; maybe getLocalCoords() should be named getRelativeCoords(), as the return value is a relative vector referred to the plane.

Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master