NAWQAAN-206

Flow duration plot is hooked up and working, currently there is only one entry for both in the jstree.
The key is the flot canvas plugin.  If you notice the canvas:true on the main plot config, that is available for plugins to assume they can write to the canvas.  After that, the plugin may define how stuff makes it to the canvas (extra config options, etc).  The only problem with these is the legend, which I think we are going to need to do something special with anyway (doesn't integrate with symbol plugin).  I've played around with getting the plot exported, and the legend is the only missing thing.