ENYO-1631: Fix bug that occurred when overriding minMax
ENYO-1631: Fix bug that occurred when overriding minMax

If a subkind of NewDataList overrides calculateMetrics and changes
the calculation of the threshold.minMax value, we want that
override to apply to the mirror-image 'maxMin' value that is
calculated in the scroll handler.

Enyo-DCO-1.1-Signed-Off-By: Gray Norton (gray.norton@lge.com)

PKRoma/enyo,PKRoma/enyo,enyojs/enyo,enyojs/enyo