In purely forward-looking models ghx is empty and sylvester3a gives a "Operands to the || and && operators must be convertible to logical scalar values" error, as e becomes a "1×0 empty double row vector" and not a logical.
* removed sylvester3.m and sylvester3a.m (have been moved to gensylv/ subdir)
* display an error message when dynare called without argument
git-svn-id: https://www.dynare.org/svn/dynare/dynare_v4@1852 ac1d8469-bf42-47a9-8791-bf33cf982152