Remove unused env arg to #respond.
First crack at also lazy-loading the HTTP headers.
Remove extra whitespace.
Add rack handler so 'rackup -s RubyletJetty' works with rack 1.2.
Implement more Hash method in Rubylet::Environment to appease Rails 3.0.
Add Rails 3.0 example to integration tests.
Small refactor in Rubylet::Environment#fetch_lazy.
Add spec test for Rubylet::Environment's muultiple layers of data.