[coor/api] * discretizer does not use a default instance, since this leads dramatic side effects.            * import impl with underscores
[coor/api] * discretizer does not use a default instance, since this leads dramatic side effects.
           * import impl with underscores

arokem/PyEMMA,trendelkampschroer/PyEMMA,trendelkampschroer/PyEMMA,arokem/PyEMMA