[TD]SectionView/ComplexSection - preview, direction selection

- add preview/live update to TaskSectionView & TaskComplexSection
- add view direction selector to uis
- use SectionNormal as Direction.  Make Direction read-only
- simplify section line end point calculation
- section group command in toolbar
- make section and complex section icons consistent
- fix compsolid cutting tool
- terminology: single/piecewise to offset/aligned

src/Mod/TechDraw/App/GeometryObject.cpp

@@ -189,7 +189,7 @@ void GeometryObject::projectShape(const TopoDS_Shape& inShape,
             visHard    = hlrToShape.VCompound();
             BRepLib::BuildCurves3d(visHard);
             visHard = invertGeometry(visHard);
-            BRepTools::Write(visHard, "GOvisHard.brep");            //debug
+//            BRepTools::Write(visHard, "GOvisHard.brep");            //debug
         }
 
         if (!hlrToShape.Rg1LineVCompound().IsNull()) {