f4c01a43bc2882e7fd18f3cd82344fff9644088c Introduce new syntax for shifting backward or forward a dynSeries object.

================================ DYNARE MAKE CHECK MATLAB RESULTS ================================ | TOTAL: 203 | PASS: 201 | FAIL: 1 | XFAIL: 1 | XPASS: 0 | LIST OF FAILED TESTS: | * run_reporting_test_matlab.m

================================ DYNARE MAKE CHECK OCTAVE RESULTS ================================ | TOTAL: 201 | PASS: 199 | FAIL: 1 | XFAIL: 1 | XPASS: 0 | LIST OF FAILED TESTS: | * run_reporting_test_octave.m

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