Add a new PropertyType enum Prop_NoRecompute to reduce possible inconsistencies between touched and recomputed features.

At the moment many feature classes lack of the mustExecute() method and thus can cause a touched feature not to be recomputed and causes the feature to be in a broken state.
Now this new enum value virtually makes the mustExecute() superfluous and thus guarantees to recompute a feature if a modified property has not set the Prop_NoRecompute flag.

On the other hand there are properties that should only touch a feature but not enforce a recompute. This guarantees a better performance and avoids unnecessary recomputes.
For example this is useful for placements where a change can be applied on-the-fly and the feature is up-to-date. Other features that depend on the touched feature will still be recomputed.

src/App/DocumentObject.cpp

@@ -527,9 +527,13 @@ void DocumentObject::onChanged(const Property* prop)
         _pDoc->signalRelabelObject(*this);
 
     // set object touched if it is an input property
-    if (!(prop->getType() & Prop_Output))
+    if (!(prop->getType() & Prop_Output)) {
         StatusBits.set(ObjectStatus::Touch);
-    
+        // must execute on document recompute
+        if (!(prop->getType() & Prop_NoRecompute))
+            StatusBits.set(ObjectStatus::Enforce);
+    }
+
     //call the parent for appropriate handling
     TransactionalObject::onChanged(prop);
 }