updated license header [ci skip]

...n/java/com/xeiam/xchart/demo/charts/line/LineChart04.java

...n/java/com/xeiam/xchart/demo/charts/line/LineChart05.java

.../com/xeiam/xchart/demo/charts/scatter/ScatterChart01.java

.../com/xeiam/xchart/demo/charts/scatter/ScatterChart02.java

.../com/xeiam/xchart/demo/charts/scatter/ScatterChart03.java

.../com/xeiam/xchart/demo/charts/scatter/ScatterChart04.java

...java/com/xeiam/xchart/demo/charts/theme/ThemeChart01.java

...java/com/xeiam/xchart/demo/charts/theme/ThemeChart02.java

...java/com/xeiam/xchart/demo/charts/theme/ThemeChart03.java

xchart/src/main/java/com/xeiam/xchart/CSVExporter.java

xchart/src/main/java/com/xeiam/xchart/CSVImporter.java

xchart/src/main/java/com/xeiam/xchart/ChartBuilder.java

xchart/src/main/java/com/xeiam/xchart/ChartColor.java

xchart/src/main/java/com/xeiam/xchart/StyleManager.java

xchart/src/main/java/com/xeiam/xchart/XChartPanel.java

xchart/src/main/java/com/xeiam/xchart/internal/Utils.java

...xchart/internal/chartpart/AxisTickBarChartCalculator.java

...m/xeiam/xchart/internal/chartpart/AxisTickCalculator.java

...iam/xchart/internal/chartpart/AxisTickDateCalculator.java

...art/internal/chartpart/AxisTickLogarithmicCalculator.java