Add identifiers for variables, properties, policies and modules. This will allow QtCreator to show relevant documentation if it learns more about the context of the contents of cmake files.
This is necessary in order for the QHelpEngineCore::linksForIdentifier API to work. http://doc-snapshot.qt-project.org/qt5-5.3/qhelpenginecore.html#linksForIdentifier That API is used by QtCreator to enable contextual links to help files.