wltp_db: Freshly rerun with proper class (not forcing class3b to all).

* Also removed 1039 bad vehicle.
wltp_db: Update TESTS for Heinz-results unforced class3b.
wltp_db: HONOR unladen_mass & v_max from Heinz.

* Update wltp_db TESTS.
* log: core: Reduce clutter from too many revolutions :-)
docs: Update CHANGES.

* model: Add ``downscale_factor_thereshold`` in the model.