valueFormatter and axisLabelFormatter

## Multiple y-axes

This demonstrates how the valueFormatter and axisLabelFormatter options work. The valueFormatter controls the display of the legend. The axisLabelFormatter controls the display of axis tick marks. These can be set on a per-axis basis.

- xvf = x-axis valueFormatter
- yvf = y-axis valueFormatter
- y2vf = secondary y-axis valueFormatter
- xalf = x-axis axisLabelFormatter
- yalf = y-axis axisLabelFormatter
- y2alf = secondary y-axis axisLabelFormatter