Improve the canvas render loop.

[erbriones]

The current render loop iterates over all points sent to the client side. The rendering is triggered whenever the canvas is zoomed or panned. Additionally, the rendering is performed in a nonblocking manner. A suggest method to improve the performance would be implementing a Quad tree.

[erbriones]

A first attempt is a two level binning algorithm decided on 9/26/2013. The canvas is split into vertical bins then subdivided into horizontal bins. The algorithm will then render the bins as a single point when the pixel density of the objects in the bins renders to the same pixel. Otherwise, the contents of the bin will be rendered.