Added new models to accommodate Chicago data.  Added populate methods too.  TODO: add individual calls to popualte_all list, in correct order.
Fixed a bug in the deterministic pp model relating to recomputing bandwidths on each iteration.  Now slower unfortunately.
Deterministic method STILL fails to work on simulated data, though it is OK when the correct P is provided initially, even with some noise present.  Conclusion: many local optima traps for deterministic EM.
Fixed selection of xrange in plotting multiplots.