Use the TEXT_OFFSET_PERCENTAGE variable when determining the text off…

…set. This allows users to just override this variable, instead of having to modify the code to get the percentages closer to the pie graph

lib/gruff/pie.rb

@@ -92,7 +92,7 @@ def draw_label(center_x, center_y, angle, radius, amount)
     x_offset = center_x # + 15.0 # The label points need to be tweaked slightly
     y_offset = center_y  # This one doesn't though
     radius_offset = (radius + r_offset)
-    ellipse_factor = radius_offset * 0.15
+    ellipse_factor = radius_offset * TEXT_OFFSET_PERCENTAGE
     x = x_offset + ((radius_offset + ellipse_factor) * Math.cos(angle.deg2rad))
     y = y_offset + (radius_offset * Math.sin(angle.deg2rad))