New Integrator and Particle System pushed to next


Hello all,

I’ve just pushed to the next branch the changeset the introduce the new Particle System and Integrator classes. This completely eliminates the previous error-probe buffer-swap mechanism, replaced by associating to each buffer one (or more) “states” of the particle system. Additionally, the sequence of commands to complete a full integration step, as well as the phases they are associated to, are now wrapped into a dedicated Integrator class, which currently has a single concrete specialization, the PredictorCorrector that implements the same flow as usual.

I have verified that the existing problems (plus a few user problems) provide the same results, but as usual with these massive changes, additional validation is always welcome.