adbecb6fc9ed26bfdc968c36595aeb78d2a878ba doc: reporting: minor clarifications. closes #687

================================ DYNARE MAKE CHECK MATLAB RESULTS ================================ | TOTAL: 480 | PASS: 469 | FAIL: 9 | XFAIL: 2 | XPASS: 0 | LIST OF FAILED TESTS: | * gsa/ls2003.mod | * fs2000/fs2000_calib_dseries.mod | * identification/kim/kim2.mod | * identification/as2007/as2007.mod | * ep/rbc.mod | * ep/rbc2.mod | * ep/rbcii.mod | * ep/linearmodel.mod | * deterministic_simulations/homotopy.mod

================================ DYNARE MAKE CHECK OCTAVE RESULTS ================================ | TOTAL: 478 | PASS: 467 | FAIL: 9 | XFAIL: 2 | XPASS: 0 | LIST OF FAILED TESTS: | * fs2000/fs2000_calib_dseries.mod | * identification/kim/kim2.mod | * identification/as2007/as2007.mod | * ep/rbc.mod | * ep/rbc2.mod | * ep/rbcii.mod | * ep/linearmodel.mod | * deterministic_simulations/homotopy.mod | * ../matlab/@dseries/detrend.m#1

A full log can be found on karaba in '/tmp/dynare-master-check-t7hrBmfhOK.log'.