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/Gui/Workbench.cpp

@@ -72,6 +72,13 @@ Gui::MenuItem* Workbench::setupMenuBar() const
           << "Separator"
           << "Part_MakeTube";
 
+    Gui::MenuItem* copy = new Gui::MenuItem;
+    copy->setCommand("Create a copy");
+    *copy << "Part_SimpleCopy"
+          << "Part_TransformedCopy"
+          << "Part_ElementCopy"
+          << "Part_RefineShape";
+
     Gui::MenuItem* bop = new Gui::MenuItem;
     bop->setCommand("Boolean");
     *bop << "Part_Boolean"
@@ -113,8 +120,7 @@ Gui::MenuItem* Workbench::setupMenuBar() const
           << "Part_ShapeFromMesh"
           << "Part_MakeSolid"
           << "Part_ReverseShape"
-          << "Part_SimpleCopy"
-          << "Part_RefineShape"
+          << copy
           << "Part_CheckGeometry"
           << "Part_Defeaturing"
           << "Separator"
@@ -144,6 +150,7 @@ Gui::MenuItem* Workbench::setupMenuBar() const
     *measure << "Part_Measure_Linear"
              << "Part_Measure_Angular"
              << "Separator"
+             << "Part_Measure_Refresh"
              << "Part_Measure_Clear_All"
              << "Part_Measure_Toggle_All"
              << "Part_Measure_Toggle_3d"
@@ -211,6 +218,7 @@ Gui::ToolBarItem* Workbench::setupToolBars() const
     *measure << "Part_Measure_Linear"
              << "Part_Measure_Angular"
              << "Separator"
+             << "Part_Measure_Refresh"
              << "Part_Measure_Clear_All"
              << "Part_Measure_Toggle_All"
              << "Part_Measure_Toggle_3d"