MS-SBVAR: Octave compatibility fix (add missing filename extensions, not added automatically under Octave)

Fixed bug in dynare_resolve (wrong calling sequence introduced in commit #013c599e).

Removed globals from DsgeVarLikelihood and changed the calling sequence. As in DsgeLikelihood, the penalty is now a
persistent variable.

Added a global structure for the data: dataset_.

Removed globals from dsgevar_posterior_density and mode_check.

Simplification of the clode, definition of the variable objective_function at the top of dynare_estimation_1 (equal
to 'DsgeLikelihood' or 'DsgeVarLikelihood').

Correction of the previous commit (3412d5e2). Set options_.lik_init=3 if lik_init==1 and unit_root_vars
keyword appears in the mod file.

keyword is present in the mod file, by forcing options_.lik_init to be equal to 3 (diffuse kalman
filter).

Correct a bug related to the number of minimum feedback variables reported during the preprocessing step

Added a test on the first input argument. If func is a function handle, then str2func should not be used.