use scala-idiomatic JFreeChart wrapper

scala-chart is a scala-idiomatic wrapper around JFreeChart. This is an
initial commit to use it in scalameter. I hope this will improve working
with charts. Let me know if you are interested in this and in more. Next
commit would be about more idiomatic dataset creation.
XYLine uses scala-chart for dataset
scaladoc for the do nothing chart report method
Merge pull request #62 from wookietreiber/wip-scala-chart

use scala-idiomatic JFreeChart wrapper