Compute examples and class distributions in tree nodes.
Merge pull request #140 from thocevar/tree

Compute examples and class distributions in tree nodes.
Add sampling option to heatmap widget.
Merge pull request #142 from astaric/heatmap-on-sample

Add sampling option to heatmap widget.
Added color scale options.
Time-based sampling on heatmap.
Insure at least some coloring for non zero cells.
Merge pull request #144 from astaric/time-based-sampling

Time-based sampling on heatmap.
Use the actual maximum contingency value for scaling factor.

Before the maximum value in the root was used.
Change sampling options.
Undo change to n_bins.
Merge pull request #145 from ales-erjavec/heatmap

Heatmap color scale
Revert to no outlines.
Add distance measures

Added distance measure Eulidean, Mahalanobis, SpearmanR, SpearmanAbsolute, PearsonR, PearsonRAbsolute
Replaced broken test
Merge pull request #139 from nikicc/distances

Add distance measures
Move sharpen to sampling part of controls.
Show more durations in sampling options.
Option to cache samples.
Prefix sample tables with underscores.