Another attempt to fix placement-related problems

transformGeometry was converting circles into B-splines. transformShape
seems to do the business: circles preserved, no placement problems so
far

CompoundFilter.py

@@ -143,7 +143,7 @@ class _CompoundFilter:
             obj.Shape = Part.makeCompound(rst)
         else: # don't make compound of one shape, output it directly
             sh = rst[0]
-            sh = sh.transformGeometry(sh.Placement.toMatrix())
+            sh.transformShape(sh.Placement.toMatrix(),True) #True = make copy
             sh.Placement = FreeCAD.Placement()
             obj.Shape = sh