integrate rack class when running cgi mode
update send_body to latest Rack::Handler::CGI version
remvoe Gemfile.cgi, it works with Rack now
to use Rack::Handler::CGI.send_body instead of stolen method
Content-Type is moved to dispatcher
style
added group for all gems in Gemfile, because cgi mode doesn't require these gems
ignore unused gems when packaging task
manually merged integration-rack branch