src/Pure/Tools/update_then.scala
2016-04-03 wenzelm 2016-04-03 prefer internal tool;
2016-02-28 wenzelm 2016-02-28 tuned signature;
2016-02-28 wenzelm 2016-02-28 moved getopts to Scala;
2015-09-21 wenzelm 2015-09-21 added isabelle update_then;