Part: changes to Part Module

* Added Part::Feature::getTopoShape/getShape() function that can obtain
  shape from any object with proper implementation of getSubObject(). It
  can even construct compound from group object with proper implementation
  of getSubObjects().

* Modified ViewProviderExt to work on any object, because it now obtain
  the shape using Part::Feature::getShape()

* Modified various Part features to obtain base/tool shapes using
  Part::getShape(), which allows them to be any type of object,
  including Link and groups.

* Modified various Part command to relax type requirement on selected
  objects.

* Add support of link and group to dimension, and add dimension refresh
  command

* Support link and group in simple command command, and add a few more
  copy command variations.

* Add special handling of 'Shape' attribute in PropertyContainerPy and
  use Part::Feature::getShape() to return shape for any object without
  Shape property. This allows many python feature work with any object
  without modification.

* GeometrySurface/CurvePy, add convenience attribute 'Rotation'

* TopoShapePy:

    * Extended support of sub shape attribute, e.g. Compound1, Solid2,
      SubShape3 ('SubShape' is used to access child shape of a compound)

    * makeWires(), new API to sort and return wires given a list of edges.

    * transformed/translated/rotated/scaled(), return a new shape with
      some transformation.

    * findPlane(), find the plane of a planar shape

    * isCoplanar(), check if two shape are coplanar

src/Mod/Part/App/GeometryCurvePyImp.cpp

@@ -28,6 +28,7 @@
 # include <gp_Dir.hxx>
 # include <gp_Vec.hxx>
 # include <gp_Pln.hxx>
+# include <gp_Quaternion.hxx>
 # include <GCPnts_UniformAbscissa.hxx>
 # include <GCPnts_UniformDeflection.hxx>
 # include <GCPnts_TangentialDeflection.hxx>
@@ -851,6 +852,17 @@ PyObject* GeometryCurvePy::intersect(PyObject *args)
     return 0;
 }
 
+Py::Object GeometryCurvePy::getRotation(void) const
+{
+    Handle(Geom_Conic) s = Handle(Geom_Conic)::DownCast(getGeometryPtr()->handle());
+    if(!s)
+        return Py::Object();
+    gp_Trsf trsf;
+    trsf.SetTransformation(s->Position(),gp_Ax3());
+    auto q = trsf.GetRotation();
+    return Py::Rotation(Base::Rotation(q.X(),q.Y(),q.Z(),q.W()));
+}
+
 PyObject* GeometryCurvePy::reverse(PyObject *args)
 {
     if (!PyArg_ParseTuple(args, ""))