Graphics - Add property ItemStyleSet with options like the border style (solid, dotted, dashed) for each line

[PauloRech]

The idea is to use a matrix (ItemStyleSet) to define the style of each line, according to the number of series.
The same way the property ItemColorSet is used to define the lines' color.
So, besides the color, we can use the style (solid, dotted, dashed) to present a data sequence.