Take selectionShift into account when displaying pie chart

[pmairoldi]

For pie charts, the chart will get cut off when selected since the main circle does not take into consideration how far the selection will go. A fix would be to take the selectionShift into account when drawing the main circle. So instead of the current width and height it would be width - (selectionShift * 2) and height - (selectionShift * 2). This would make the chart inset by the selectionShift so that when selected the chart would fit inside the view. An example of this happening can be seen below.