changed test to get TestMailer to use :file delivery method directly (as setup action was resetting delivery_method to :test on init

Added delivery_handler method to mail and implemented in ActionMailer to deliver inside of instrumentation

Conflicts:
	actionmailer/lib/action_mailer/mail_helper.rb
	railties/lib/rails/configuration.rb

Signed-off-by: NYehuda Katz <wycats@Yehuda-Katz.local>

Less places you need to change if you rename your application.

Adding failing tests for calling just the action, instead of :create_action_name and :deliver_action_name