Add macro do define accessor functions for properties.
Macro defproperty seems correct for set<Property>
Correct return value from -initialize function.
Fix set-series-index-state, replace -set... functions with defproperty

set-series-index-state was replacing the entire series-index with the series
being updated.  This came from attempt to return current value of the series.

The defproperty macro will create several functions, including the setters.