Added a method to scene that collects all the html files for the visualization.

The visualizations don't work for all browsers when running through the server,
but it may work by simply opening the files in the browser directly without a
server. This adds a method to give access to those files in the current
directory.
Merge pull request #66 from pydy/static-scene

Added a method to scene that collects all the html files for the visuali...