Several PointsProviders are available in a on GraphView
Switched to Plot(contains style and pointsProvider)
Finished with ability to add several plots to one GraphView
In algorithm for choosing minScaleStep List switched to treeSet + logic in comparators
Labels for x-axis are draws using align.center
Fixed position of y-labels
Description of defaut plot style in Java-Doc
Merge pull request #8 from anastasia-zaitsewa/issue-7

Issue 7 Plots (contains PlotStyle, PointsProvider and additional elements to be used by Graph)