adding creation of <fname>_set_auxiliary_variables.m containing recursive definition of auxiliary variables

  + the number of static, lag, lead and both variables,
  + the lead_lag_incidence matrix for variables related to previous blocks
  + the index of reordered policy rule
for each block during the preprocessing step
- correct a bug in the comment related to first order derivatives in _dynamic.m file for a block decomposed model without bytcode
- avoid simplification of the Jacobian matrix (setting to zero all elements below the cutoff) for  estimated or stochastically simulated models: the cutoff option is set to 0.

- If a case is not handled, the equation is supposed to be impossible to normalize.
- comments added to describe the normalization process

like "x = { 'foo' 'bar' };" was incorrectly passed on to MATLAB)

MS-SBVAR: added automatic saving of graphs in <mod_name>/Output; added possibility to select endogenous variables for IRF plots; updated plot functions.

renamed ramsey_policy_discount_factor by optimal_policy_discount_factor because it is also used by discretionary_policy