fix plot_estimated_dist() for binned mode

- add data argument to VonMisesMixture.plot_dist()
show all parameter sets in summary sorted by fit quality

- update make_summary(), print_summary()
rename examples/parameter_sets.py -> examples/psets/n_components.py
update examples/psets/n_components.py to use binned fitting
new examples/psets/models.py, examples/psets/start_parameters.py
use parameter set ids in plot file names

- update analyze(), plot_estimated_dist(), plot_histogram_comparison()
ENH: log chisquare statistics
use MixtureResult already in VonMisesMixture.fit()
new VonMisesMixture.gof_chisquare() for consistent interface

- store source data in model object
update examples/ex_fit_vonmises.py for chisquare logging
show chisquare statistics and criteria values in summary

- update make_summary(), print_summary()