Displayed points for series in the graph.

[pryaniq]

How use: yourSeriesName1.points = true yourSeriesName1.points = false chart.poinstWidth = 2.0

[gpbl]

Hi @pryaniq thanks for your PR! I really appreciate the help. The points (better called markers) are a nice addition to the chart.

However I think we should provide a way to use a custom marker, e.g. I would not hard code the layer into the Chart class. I wonder also if we should provide methods for touch events.

There are some things in the code I have not clear – and performance improvements I'd like to apply (see comments). Would you mind to discuss the feature before going on with the PR?

[gpbl]

For example, each ChartSerie may have its own marker definition.

[pryaniq]

@gpbl thanks for review. I will try to fix the code, according to the comments.