message: add support for a JSON list of selected atoms
  Based on discussions:
diff: @@ -458,6 +458,14 @@ bool InterfaceScript::insertMolecule(QJsonObject& json,
  if (m_moleculeExtension == QLatin1String("None"))
  return true;
  + // insert the selected atoms
  + QJsonArray selectedList;
  + for (Index i = 0; i < mol.atomCount(); ++i) {
  + if (mol.atomSelected(i))
  + selectedList.append( (qint64)i );
  + }
  + json.insert("selectedatoms", selectedList);
  +
  Io::FileFormatManager& formats = Io::FileFormatManager::instance();
  QScopedPointer<Io::FileFormat> format(
  formats.newFormatFromFileExtension(m_moleculeExtension.toStdString()));
  