Suppression of the ErrorEllipseStyleAccessor
Suppression of ErrorEllipseChartStyleAccessor
Removed the StyleAccessor
Removed useless method in ErrorEllipseChart
Plotter is now a bit simplier (the chart is templates)
Button added to the empty chart
Fixes #19
Merge branch 'dev' into canary

* dev:
  Button added to the empty chart Fixes #19
  Plotter is now a bit simplier (the chart is templates)
  Removed useless method in ErrorEllipseChart
  Removed the StyleAccessor
  Suppression of ErrorEllipseChartStyleAccessor
  Suppression of the ErrorEllipseStyleAccessor