a5be9dd845f53cc260b1bd37e7f2350833dfb3c4 Add trust-region nonlinear solver.

================================ DYNARE MAKE CHECK MATLAB RESULTS ================================ | TOTAL: 432 | PASS: 430 | FAIL: 0 | XFAIL: 2 | XPASS: 0

================================ DYNARE MAKE CHECK OCTAVE RESULTS ================================ | TOTAL: 430 | PASS: 428 | FAIL: 0 | XFAIL: 2 | XPASS: 0

A full log can be found on karaba in '/tmp/dynare-master-check-zF81XlGXc8.log'.