Integrated DifferenceChart into PAVO

...ls/descartes/pavo/controller/VisualizationController.java

...avo/src/tools/descartes/pavo/result/SeriesResultPavo.java

...avo/src/tools/descartes/pavo/rubbish/EnumDiagramtype.java

...scartes.pavo/src/tools/descartes/pavo/types/BarChart.java

...escartes.pavo/src/tools/descartes/pavo/types/BoxPlot.java

....pavo/src/tools/descartes/pavo/types/DifferenceChart.java

...escartes.pavo/src/tools/descartes/pavo/types/HeatMap.java

...o/src/tools/descartes/pavo/types/IVisualizationType2.java

...cartes.pavo/src/tools/descartes/pavo/types/LineChart.java

...scartes.pavo/src/tools/descartes/pavo/types/PieChart.java