Large amounts of data makes HSL very slow

RussNelson[CodePlex]
We have a large amount of data in our database. HydroServerLite tries to load the entire set of data points. On a reasonably powerful machine, it can take up to 9 minutes for some sites to load. HSL should send back an excerpt of the data (2000 points
max over the entire data series, I suggest), and mark it as an exerpt. I think that the proper solution to this is to have greater cooperation from the graphing javascript, so that when it gets back a data series, it knows that the data series is an excerpt,
so that when the user adjusts the size of the plot, it will re-fetch a smaller excerpt. I'm not familiar enough with Highcharts to know if it can do this via callbacks.