preprocessor

- mfs: new option for 'steady' and 'model' commands. Determines the equation belonging to the set of feedback variables.
  mfs = 0 => all variables are considered as feedback variables (default value)
  mfs = 1 => using only naturally normalized equation as potential recursive equations (all variables assigned to unnormalized equations are considered as feedback variable)
  mfs = 2 => adding to the set of potential recursive equation with mfs = 1 the linear equation in endogenous variable normalized (all variables assigned to nonlinear unnormalized equations are considered as feedback variable)
  mfs = 3 => adding to the set of potential recursive equation with mfs = 2 the non linear equation in endogenous variable normalized
- correction of few buggs in simulate.dll
- block_mfs_dll: new option for 'steady' command. Use simulate.dll to solve the steady state model (speedup the computation of the steady-state and the homotopy)

git-svn-id: https://www.dynare.org/svn/dynare/trunk@2866 ac1d8469-bf42-47a9-8791-bf33cf982152