Moved method getAttributes() from class BasicEventImpl to interface BasicEvent, such that the events-writer can also use the basic interfaces. Restructured EventWriterTXT to also use getAttributes() instead of getTextRepresentation(). some other code cleanup in the events-package. new reference-files for some tests because AgentReplanEvent is no longer written to TXT-Events-files (the written info was useless and couldn't be read in anyway).