Allow configuration of MultiplePiePlot and avoid NPE in setSectionColors() if plot is MultiplePiePlot. Method setSectionColors() taking values, key *and* colour, from <sectionColors> does not work as expected I would say, so need to think about that and add a solution later.
Merge pull request #12 from ljo/feature/avoid-npe-multiple-pie-plot

Allow configuration of MultiplePiePlot and avoid NPE in setSectionColors...