Added print-object methods for summaries.
Made arguments more general, added ensure-arguments-alist.
Removed macros that add and map, they are superfluous.
Added map-df and mapping-df, also removed some line breaks in docstrings.
Removed some linebreaks.
Added map-df and mapping-df to export list.
Defined mask so that it can be reused.
Fixed bug.
Added unit tests for map-df and mapping-df.