for empty history.results add series to dataset

This had been missing -- either my addition is correct or there is no
point in even creating the series -- what is it?
extracts ciFor function
scala-idiomatic CategoryDataset creation

A ToCategoryDataset converter is used to convert the
Seq[(String,(String,Double))] of the for loops for both histograms. The
rest is basically un-nesting the for loops to yield the data and dead
code elimination.
Merge pull request #64 from wookietreiber/wip-scala-chart

further scala-chart additions