Support for transperency in a fill

flot seems to support transparency in a fill, by passing in a number between 0 
to 1 instead of a boolean to the "fill" attribute.

However the gFlot api only allows passing of true or false. Could we have a 
simple overridden method that also supports a double?

Reference:
http://people.iola.dk/olau/flot/API.txt

  series: {
    lines, points, bars: {
      show: boolean
      lineWidth: number
      fill: boolean or number
      fillColor: null or color/gradient
    }

"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 which are filled with white), the fill color is auto-set to the
color of the data series. You can adjust the opacity of the fill by
setting fill to a number between 0 (fully transparent) and 1 (fully
opaque).

Original issue reported on code.google.com by bas...@gmail.com on 13 Jan 2011 at 1:39

miunsi63 / gflot

Support for transperency in a fill #31