**Fixes**:
- clustering: fixed serious bug in **minRMSD** distance calculation, which led to
lots of empty clusters. The bug was introduced in version 2.1. If you used
this metric, please re-assign your trajectories. 825
- clustering: fixed KMeans with minRMSD metric. 814
- thermo: made estimate_umbrella_sampling more robust w.r.t. input and fixed doumentation. 812 827
- msm: low-level api usage deprecation warnings only show up when actually used.