added style manager

.../src/main/java/com/xeiam/xchart/demo/charts/Example1.java

...src/main/java/com/xeiam/xchart/demo/charts/Example10.java

.../src/main/java/com/xeiam/xchart/demo/charts/Example2.java

.../src/main/java/com/xeiam/xchart/demo/charts/Example4.java

.../src/main/java/com/xeiam/xchart/demo/charts/Example8.java

.../src/main/java/com/xeiam/xchart/demo/charts/Example9.java

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

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

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

xchart/src/main/java/com/xeiam/xchart/appearance/Series.java

...rc/main/java/com/xeiam/xchart/appearance/SeriesColor.java

...ain/java/com/xeiam/xchart/appearance/SeriesLineStyle.java

...c/main/java/com/xeiam/xchart/appearance/SeriesMarker.java

...c/main/java/com/xeiam/xchart/appearance/StyleManager.java

...in/java/com/xeiam/xchart/internal/chartpart/AxisPair.java

...a/com/xeiam/xchart/internal/chartpart/AxisTickLabels.java

...va/com/xeiam/xchart/internal/chartpart/AxisTickMarks.java

...n/java/com/xeiam/xchart/internal/chartpart/AxisTitle.java

.../java/com/xeiam/xchart/internal/chartpart/ChartTitle.java

...main/java/com/xeiam/xchart/internal/chartpart/Legend.java