when necessary

doesn't work yet; now Jacobian is singular

allow the possibility to close all slaves from a condition found in one single thread (e.g. in a while loop where all threads look for the verification of a condition in a loop)

manually cherry picked from 4.2. branch:
1a5a294c

specially useful when neighborhood_width is used

Added calls to matlab implementation of the perfect foresight solver in homotopic routine (extended path approach).

Changed the test files conformably to the latest commits related to the (stochastic) extended path approach.

Note that, even for small models, there is a (very) substantial gain in using the use_dll option.

Added an option to skip the test on the number of periods over which the perfect foresight models are solved.

Oups! I forgot to add this routine in commit ac54f7f5. This routine provides a matlab implementation of the perfect foresight model solver.

Changed the default value of options_.ep.fp. Test the stability of the solution only for the first period (when the value of periods is increased).