Cosmetic. Renamed hh (figure handle not to be confused hessian matrix) as fh.
Changes related to the treatment of the (optionally) provided mode file.

(1) Added more checks on the content of the provided mode file compared the the list of declared parameters (the condition on the number of parameters is not strong enough).

(2) Added a mechanism to adapt the content of the mode file if possible. For instance, if the estimated parameters are a subset of the parameters in the mode file, we only need to discard some of the parameters in the mode file.

(3) Added output argument in dynare_estimation_init, which returns the hessian matrix (hh) with the estimated mode.