Added draw hook

git-svn-id: https://flot.googlecode.com/svn/trunk@167 1e0a6537-2640-0410-bfb7-f154510ff394

API.txt

@@ -923,6 +923,16 @@ Currently available hooks (when in doubt, check the Flot source):
    Note that you must leave datapoints in a good condition as Flot
    doesn't check it or do any normalization on it afterwards.
 
+
+ - draw  [phase 5]
+
+   function(plot, canvascontext)
+ 
+   Hook for drawing on the canvas. Called after the grid is drawn
+   (unless it's disabled) and the series have been plotted (in case
+   any points, lines or bars have been turned on). For examples of how
+   to draw things, look at the source code.
+   
  
  - bindEvents  [phase 6]
 

jquery.flot.js

@@ -113,6 +113,7 @@
             processOptions: [],
             processRawData: [],
             processDatapoints: [],
+            draw: [],
             bindEvents: [],
             drawOverlay: []
         },
@@ -994,8 +995,11 @@
         function draw() {
             if (options.grid.show)
                 drawGrid();
+
             for (var i = 0; i < series.length; ++i)
                 drawSeries(series[i]);
+
+            executeHooks(hooks.draw, [ctx]);
         }
 
         function extractRange(ranges, coord) {