colorScale will change its returned scale value based on how many times it has looped
Use lighten instead of darken.  Use hsl
Removing unneeded instance vr
Use lightenColor
Remove semicolon
darkened -> lightened
colorScale test
Adding lighten darken unit tests
Pass metadata to projectors in interactions.
Merge branch 'develop' into interaction_metadata
Metadata on AbstractBarPlot.
stack.
Move stacking to metadata and don't modify data.
Merge branch 'develop' into metadata_stacking

Conflicts:
	plottable.js
Factor out magic number
Move clustering logic to metadata.
Fix auto scale domain on stacked plot.

It uses stacked logic in metadata.

Close #1340.
Merge branch 'develop' into metadata_stacking

Conflicts:
	plottable.js
All unexposed vars are underscored
Formatting.