Changes

Summary

1. tuned output;
2. tuned message -- more parsable;
3. tuned signature;
4. identify managed repository clones;
5. some timing and logging, similar to old isatest.log;
6. enforce short name, notably on Mac OS X;
7. tuned -- Date.Format.default used by toString;
8. clarified modules;
9. force fresh build;
10. basic setup for Isabelle cronjob;
11. tuned;