Changes

Summary

1. merged
2. tuned;
3. proper columns;
4. tuned signature;
5. more general signature: not limited to SQLite;
6. suppress inlined properties from log output;
7. prefer database, but also accept log.gz from historic versions;
8. more robust JDBC initialization, e.g. required for Isabelle/jEdit startup;
9. maintain persistent session info in SQLite database instead of log file;
10. tuned;
11. tuned signature;
12. tuned;
13. tuned message;
14. clarified signature;
15. more selective queries;
16. clarified data representation;
17. data representation with XML.Cache; tuned;
18. clarified name;
19. SQL database operations for combined session info;
20. prefer non-strict default;
21. clarified signature (again, see also 3ed43cfc8b14);
22. tuned signature;
23. tuned;
24. tuned comments;
25. clarified message: exception output usally happens in a context without extra newline;