Increased default number of particles.
Changed local variable name (index of the main loop).
Added option number_of_particles (estimation command, non linear filters).
Do not consider variables that are not column vectors.
Fixed bugs:

(1) The non_linear_dsge_likelihood routine was not adapted to the last changes related to the way data are handled.

(2) The removal of the trend was missing.
Added option resampling (estimation command, non linear filters).
Added option resampling_threshold (estimation command, non linear filters).
Added option resampling_method (estimation command, non linear filters).
Added filter_algorithm (estimation command, sets the particle filter algorithm).
Bug fixes.
Added option proposal_approximation (estimation, non linear filters).
Removed useless option.
Added option distribution_proposal (estimation, non linear filters).