Changes

Summary

1. more thorough Store.clean_output (amending 1fa1b32b0379);
2. clarified signature: Build_Process tells how to clean sessions;
3. clarified signature;
4. tuned;
5. tuned;
6. minor performance tuning;
7. tuned;
8. tuned signature;
9. tuned, following 7a1153c95bf9;
10. merged
11. tuned signature: fewer warnings in IntelliJ IDEA;
12. proper usage;
13. recover "build_database_server" from 1fa1b32b0379: still required, e.g. in build_benchmark;
14. clarified signature;
15. more robust: make double-sure that heap digest is present;
16. tuned;
17. minor performance tuning: just one transaction for log_db without heap;
18. tuned;
19. proper store.cache.compress;
20. tuned whitespace;
21. clarified store_session: heap requires process_result.ok, but log_db is always stored; clarified ML_Heap.clean_entry vs. ML_Heap.init_entry;
22. unused;
23. tuned;
24. tuned names;
25. tuned names;
26. clarified database layout;
27. tuned signature; tuned messages;
28. clarified signature;
29. more accurate types;
30. build local log_db, with store/restore via optional database server; tuned messages;
31. propagate property "isabelle.debug", notably for Java/Scala exception trace;
32. tuned;
33. proper treatment of "isabelle build_process -C" (amending 0cac7e3634d0);
34. clarified signature; more robust slice_size;
35. clarified names;
36. more explicit build_cluster flag to guard open_build_database server;
37. tuned;
38. clarified signature;
39. simplified specification of type class semiring_bits