2012-07-26 wenzelm 2012-07-26 remove old output heaps, to ensure that result is valid wrt. check_stamps; tuned signature;
2012-07-26 wenzelm 2012-07-26 support session groups; tuned signature;
2012-07-24 wenzelm 2012-07-24 tuned messages (cf. isabelle makeall);
2012-07-24 wenzelm 2012-07-24 clarified build -n (no build);
2012-07-24 wenzelm 2012-07-24 timing is command line options, not system option;
2012-07-23 wenzelm 2012-07-23 added system build mode: produce output in ISABELLE_HOME; determine output location more explicitly;
2012-07-22 wenzelm 2012-07-22 parallel scheduling of jobs; misc tuning;
2012-07-18 wenzelm 2012-07-18 allow explicit specification of additional session directories;
2012-07-17 wenzelm 2012-07-17 basic setup for Isabelle build tool;