ensure objects are in the correct thread when loading

Since we load in a separate thread, when the QObject based objects are
instantiated, they're created with affinity to that separate thread. Now we
specifically ensure they are moved to the main thread after their creation.

app/node/param.cpp

@@ -282,23 +282,3 @@ QByteArray NodeParam::ValueToBytesInternal(const QVariant &v)
 
   return bytes;
 }
-
-void NodeParam::SaveConnections(QXmlStreamWriter *writer) const
-{
-  writer->writeStartElement("connections");
-
-  foreach (NodeEdgePtr edge, edges_) {
-    NodeParam* other;
-
-    if (edge->input() == this) {
-      other = edge->output();
-    } else {
-      other = edge->input();
-    }
-
-    writer->writeTextElement("connection",
-                             QString::number(reinterpret_cast<quintptr>(other)));
-  }
-
-  writer->writeEndElement(); // connections
-}