Caching and javascript decorators to speed up lessons index

Squashed commit of the following:

commit f96e0ca5fb21393ed2c614bdd2ae5518b5dc4439
Author: Gabe Kopley <gabe@coshx.com>
Date:   Tue May 21 20:48:16 2013 -0700

    Caching and javascript decorators to speed up lessons index
Add "Ruby in 100 Minutes" resource to FAQ