The change implemented in 21a8a5794a broke the
testsuite and was incomplete.
– new option “overwrite” to provide the old behaviour (used to fix the testsuite);
– when concatenating several “estimated_params” block, the preprocessor now
checks that paramateres are not declared twice across blocks.
This optimizer seems more robust accross different hardware (with other
optimizers, the algorithm does not converge to a local maximum, e.g. on the
runner "lupi").