* fixed substitution of endogenous with leads >= 2: take into account exogenous with leads in non-linear terms
* fixed substitution of exogenous with leads: take into account other variables with leads in non-linear terms


git-svn-id: https://www.dynare.org/svn/dynare/trunk@3027 ac1d8469-bf42-47a9-8791-bf33cf982152