Clarify that the default fill color of points is white

git-svn-id: https://flot.googlecode.com/svn/trunk@150 1e0a6537-2640-0410-bfb7-f154510ff394

API.txt

@@ -462,9 +462,10 @@ also hide the shadow.
 "fill" is whether the shape should be filled. For lines, this produces
 area graphs. You can use "fillColor" to specify the color of the fill.
 If "fillColor" evaluates to false (default for everything except
-points), the fill color is auto-set to the color of the data series.
+points which are filled with white), the fill color is auto-set to the
-You can adjust the opacity of the fill by setting fill to a number
+color of the data series. You can adjust the opacity of the fill by
-between 0 (fully transparent) and 1 (fully opaque).
+setting fill to a number between 0 (fully transparent) and 1 (fully
+opaque).
 
 For bars, fillColor can be a gradient, see the gradient documentation
 below. "barWidth" is the width of the bars in units of the x axis,