The new file is <FILENAME>_static_params_derives.m

Closes: #160

Replace them by equivalents in M_ (and an extra one: M_.dynamic).

IMPORTANT POINT: oo_.dr.npred used to count both purely backward and mixed/both
variables. This was the cause of lots of confusion. The new M_.npred only
counts purely backward variables.

We now have the following indentities:

M_.npred + M_.nboth + M_.nfwrd + M_.nstatic = M_.endo_nbr
M_.nspred = M_.npred + M_.nboth
M_.nsfwrd = M_.nfwrd + M_.nboth
M_.ndynamic = M_.npred + M_.nboth + M_.nfwrd

This should fix some random crashes of the preprocessor

They emit a warning under Octave

variables and probably violates Jensen inequality in some cases.

of log and pow functions so as to insure non-negative arguments

params and 1st deriv of hessian wrt to params

Error introduced in ca103726

* Correction of a bug appearing in a block decomposed model when  an observable variable are also a state variable

Displays an error message when the model contains pound expressions and 'bytecode' or 'block' options are present

347ab4d0 and corrects the earlier
ordering problem.

cosmetic: simplify jacobianHelper, hessianHelper and sparseHelper functions and fix spacing in dynamic file

  + 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.

renamed ramsey_policy_discount_factor by optimal_policy_discount_factor because it is also used by discretionary_policy

Correct a bug when the model contains deterministic exogenous variables and bytecode option is used.
Note that stochastic simulations do not work for the moment with block option.