Removed test files (non linear filters).

tests/particle/data_benchmark.m

tests/particle/data_benchmark2.m

tests/particle/data_risky.m

tests/particle/data_risky2.m

tests/particle/data_risky_perturb.m

tests/particle/dsge_base.mod

tests/particle/dsge_base_steadystate.m

tests/particle/fs2000_particle.mod

tests/particle/fs2000_particle_steadystate.m