4.0: merged r2283 changeset from trunk (constant estimation bug fix....

4.0: merged r2283 changeset from trunk (constant estimation bug fix. Diminished tolerance in recomputation of steady state for linear models)

git-svn-id: https://www.dynare.org/svn/dynare/branches/4.0@2484 ac1d8469-bf42-47a9-8791-bf33cf982152