* added an embryonic checking pass after parsing
* modified the decision of which derivatives to compute:
  - if a simul statement is present, compute the jacobian vs endogenous variables only, and no hessian
  - if a stoch_simul/estimation/olr/osr statement is present, compute the jacobian vs all variables, plus the hessian
  - if the two previous conditions are simultaneously fulfilled, abort with an error
  - if none of these two conditions are fulfilled, abort with an error (nothing to compute)
* fixed a minor bug with the size of the jacobian matrix when computing it only vs endogenous variables


git-svn-id: https://www.dynare.org/svn/dynare/dynare_v4@1120 ac1d8469-bf42-47a9-8791-bf33cf982152