Maps: Performance optimization by not updating shapes lying outside the plot area.
Maps: Some rearranging
Maps: Started implementing color axis.
Merge remote-tracking branch 'origin/master'
Maps: Support logarithmic color axis.
Maps: Worked on color axis
Fixed issue with ordinal axis and selected range being normalized to selected button even when time span doesn't allow it. Closes #2290.
Fixed regression where legend would disappear when the linkedTo option was set to null. Closes #2414.