DOC: docstrings in fit_von_mises.py
ENH: new spread_by_counts()
use spread_by_counts() in fit_von_mises.py, ex_fit_vonmises.py
ENH: add bins argument to VonMisesMixture.plot_dist(), use it
ENH: new Struct class for pretty printing of object attributes
inherit GaussianKDE, VonMisesMixture also from Struct
REF: move helper functions normalize_params to mixture_von_mises.py
ENH: add VonMisesMixtureBinned
ENH: add least-squares histogram fitting
Merge branch 'updates'