Gets or sets the scale value at which this axis should cross the "other" axis.
The value is defined in user scale units
This property allows the axis to be shifted away from its default location.
For example, for a graph with an X range from -100 to +100, the Y Axis can be located
at the X=0 value rather than the left edge of the ChartRect. This value can be set
automatically based on the state of CrossAuto. If
this value is set manually, then CrossAuto will
also be set to false. The "other" axis is the axis the handles the second dimension
for the graph. For the XAxis, the "other" axis is the YAxis. For the YAxis or
Y2Axis, the "other" axis is the XAxis.
