Sketcher: Augment malformed constraint messages

===============================================

Enable a user recomputing an object/document to identify which sketch has the malformed constraints.

src/Mod/Sketcher/App/SketchObject.cpp

@@ -286,6 +286,10 @@ int SketchObject::solve(bool updateGeoAfterSolving/*=true*/)
         }
     }
 
+    if(solvedSketch.hasMalformedConstraints()) {
+        Base::Console().Error("Sketch %s has malformed constraints!\n",this->getNameInDocument());
+    }
+
     lastSolveTime=solvedSketch.SolveTime;
 
     if (err == 0 && updateGeoAfterSolving) {