show scatter titles in these two examples

the scatter-series one i understand - we have to prevent the composite
chart from overriding the title function, since we need the special
title function that overrides the grotesque #702 scatter override of
key+value accessors

but i can't get why we don't need that for the multi-scatter
example. they're both composite charts, but this one works with the
shared composite title function because somehow or another, the key
accessor that title function sees is *not* the scatter override one.

it has something to do with the title function capturing key+value
accessors from its own closure, but i'm confused as heck and must be
tired as well.

ref #1200

Author: gordonwoodhull

web/examples/multi-scatter.html

@@ -39,6 +39,7 @@
         .yAxisLabel("This is the Y Axis!")
         .clipPadding(10)
         .dimension(scatterDimension)
+        .brushOn(false)
         .legend(dc.legend().x(70).y(10).itemHeight(13).gap(5))
         .compose([
             dc.scatterPlot(chart)

web/examples/scatter-series.html

@@ -48,6 +48,7 @@
     .dimension(runDimension)
     .group(runGroup)
     .mouseZoomable(true)
+    .shareTitle(false) // allow default scatter title to work
     .seriesAccessor(function(d) {return "Expt: " + d.key[0];})
     .keyAccessor(function(d) {return +d.key[1];})
     .valueAccessor(function(d) {return +d.value - 500;})