2.10.0

• Add multi-valued map support for selection.attr and similar methods.
• Add Lab* and HCL color spaces.
• Add d3.tween for easier customization of transition interpolators.
• Add d3.tsv for loading tab-separated values.
• Add static localization for d3.time.format, including fr_FR and ru_RU locales.
• Add a new quantitative scale: d3.scale.threshold.
• Add outer padding support for d3.scale.ordinal’s rangeBands.
• Add d3.layout.pack padding support.
• Custom interpolators can now be used with d3.svg.line and d3.svg.area.
• Add new random generators for log-normal and Irwin–Hall distributions.
• Improve d3.time.scale’s nice.
• Fix incorrect tangents with monotone interpolation.
• Simplify transform interpolation.