[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/Gui/ViewProviderViewSection.cpp

@@ -36,10 +36,12 @@
 #include <Gui/Control.h>
 #include <Gui/Selection.h>
 
+#include <Mod/TechDraw/App/DrawComplexSection.h>
 #include <Mod/TechDraw/App/DrawGeomHatch.h>
 #include <Mod/TechDraw/App/DrawHatch.h>
 
 #include "TaskSectionView.h"
+#include "TaskComplexSection.h"
 #include "ViewProviderViewSection.h"
 #include "QGIView.h"
 
@@ -123,6 +125,12 @@ bool ViewProviderViewSection::setEdit(int ModNum)
     }
     // clear the selection (convenience)
     Gui::Selection().clearSelection();
+
+    auto dcs = dynamic_cast<TechDraw::DrawComplexSection*>(getViewObject());
+    if (dcs) {
+        Gui::Control().showDialog(new TaskDlgComplexSection(dcs));
+        return true;
+    }
     Gui::Control().showDialog(new TaskDlgSectionView(getViewObject()));
     return true;
 }
@@ -133,7 +141,6 @@ bool ViewProviderViewSection::doubleClicked()
     return true;
 }
 
-
 void ViewProviderViewSection::getParameters()
 {
     Base::Reference<ParameterGrp> hGrp = App::GetApplication().GetUserParameter()