opal/opal — pull request #463 by jibi (2013-12-24 00:13:55+00:00)
Title: Use Rack::Static instead of Rack::Directory in opal-sprockets

Rack::Static is better than Rack::Directory because:

* more configurable (with root and urls parameters)
* does not capture the / request (so index request can be sent to the next application or a 404 response will be returned instead of the listing of /)

Moreover this change does not break examples.