* Add switch (setHighPrio) to MapChain to add macros LowPrio or HighPrio.
* Replace putHighPrio and putLowPrio with put. put uses one or other list depending on setHighPrio=true/false.
* Add macros inside of handleIncludeLine with 'macros.putHighPrio' (indirect by setting setHighPrio=true).
* Add second source file to test project.