clarified;

merged

fixed the simplification of Suc n - 1

tuned whitespace;

tuned message;

just one pass is sufficient (see also cc8391b92747, 3e8a897042d9);

more detailed progress for build_log_database, to see better what happens when;

clarified signature: explicit Progress date;

more uniform progress;

more robust: support concurrent output;

disable multi-builds (again): does not quite work yet;

clarified modules;

clarified signature;

clarified SEQ: more sequential evaluation to support multiple tests (see also 5c91bd51fc37);

tuned signature;

proper Compress.Cache;

clarified signature;

more parallelism via consumer thread: with mailbox limit to avoid ressource problems;

support for mailbox limit;

tuned signature;

discontinued pointless option (reverting 63d55ba90a9f): performance tuning works better via SQL.Database.execute_batch_statement;

clarified database transactions (see also 2c704ae04db1, 7bd0a250183b);

afford multiple tests on fast machines (see also edb4faf666c9 and 2a26d423d9fb); proper history_base for ARM;

performance tuning: parallel and incremental update of build_log_database;

performance tuning: more careful database access;

clarified message;

tuned signature;

tuned;

prefer old-style import "=>";

merged