[TD] avoid memory leaks by using shared_ptr

TD geometry objects are sometimes double deleted.  This
change uses shared_ptr instead of raw pointers to manage
deletions.

src/Mod/TechDraw/App/DrawDimHelper.h

@@ -53,7 +53,7 @@ class TechDrawExport hTrimCurve {
 class TechDrawExport DrawDimHelper {
     public:
     static void makeExtentDim(DrawViewPart* dvp,
-//                              std::vector<TechDraw::BaseGeom*> selEdges,
+//                              std::vector<TechDraw::BaseGeomPtr> selEdges,
                               std::vector<std::string> edgeNames,
                               int direction);
     static gp_Pnt2d findClosestPoint(std::vector<hTrimCurve> hCurve2dList,