Streamlined extended paths routines.
* Removed the necessity (for the user) to run stoch_simul bebore executing the exetended path routine (when options_.init>0). * The value of options_.ep.init defines the mix (used for the initialization of the perfect foresight solver) between the previous perfect foresight solution and the path obtained with an order one perturbation approach. * Removed timing related statements. * Changed homotopy set-up for stochastic extended path: add future multivariate innovations one by one. * Endogeneously increase step_length in the homotopy routine. * Removed homotopy_2 related code.