49506c6ec4ffc430e194b07763e5b8368d095c47 Document default for new option posterior_max_subsample_draws.

================================ DYNARE MAKE CHECK MATLAB RESULTS ================================ | TOTAL: 415 | PASS: 413 | FAIL: 0 | XFAIL: 2 | XPASS: 0

================================ DYNARE MAKE CHECK OCTAVE RESULTS ================================ | TOTAL: 413 | PASS: 411 | FAIL: 0 | XFAIL: 2 | XPASS: 0

A full log can be found on karaba in '/tmp/dynare-master-check-5feN7OVCEG.log'.