* Added way for info associated with a certain data cell to be stored in an axis via methods Axis#setDataCellScaleInfo,getDataCellScaleInfo. This solved a problem of storing by-products of the scale domain calculation code in the waterfall (_ruleInfos).
* Plots now store their generated data cells, allowing for latter retrieving the data cells of a certain role, and getting its ScaleInfo information from the axis.
* DataCells now have a key that allows an axis to store info associated to it.
* Waterfall now better supports multiple plots of its type; validates that both plots agree on water direction, by traversal modes conciliation.
* Moved _calAxesOffsetPadding from the plot panel to the chart class. This is much more efficient, and the right place to do the calculations.