Support for dynamic axis position marker

[eselmeister]

Especially when selecting data, it would be great to highlight the currently selected position at the X/Y axis.

[eselmeister]

The position markers are disabled by default. One can activate the position marker either directly

axisSettings.setDrawPositionMarker(true);

or via the axis settings:

IChartSettings chartSettings = getChartSettings();
ISecondaryAxisSettings axisSettings = getSecondaryAxisSettingsX(..., chartSettings);
axisSettings.setDrawPositionMarker(true);

A remaining issue is, that the scale on the Y axis has a slight offset. This needs further investigations.

[eselmeister]