src/Pure/Tools/check_keywords.scala
2017-05-14 wenzelm 2017-05-14 tuned;
2015-09-29 wenzelm 2015-09-29 clarified modules;
2015-04-01 wenzelm 2015-04-01 clarified module; more parallel processing;
2015-04-01 wenzelm 2015-04-01 added isabelle build option -k, for fast off-line checking of theory sources;