Added drawcalls example for buffergeometry

I've created an example of using ```drawcalls```on ```buffergeometry```to dynamically modify the number of points and lines to paint.
It's used both on a lines set and a pointcloud.

You can see here the working example:
http://kile.stravaganza.org/lab/js/examples/webgl_buffergeometry_drawcalls.html
You have am animation loop, so you do not need `controls.addEventListener()`. `OrbitControls` also does not have a `damping` property.