Minor refactor of method for computing new p matrix in-between iterations of validation.
Added to data tests and fixed some that were failing.
Added to CAD validation code, but this proving tricky - keeps bombing out with no trigger events.  TODO: test on Chicago and see if that fixes it.
Worries about norming now... ideally want to integrate the trigger_density_in_place to test it comes to the expected value.  BG does.