Add task to regenerate cache. Design/layout cleanup.

Cleaned up Gemfile and moved things to the appropriate environments.
Added rake tasks to create, wipe, or regenerate the page cache.  Added
whenever method to regenerate page cache each day at 4:30 EST. Cleaned
up design and layout (added labels and banners, minor change to
colors). Moved compass config.rb to /config dir. Added last_updated_at
info to cache and displayed on home page.