resque-async_deliver 1.0.0

This gem makes it possible to send mails asynchronously using Resque by simply rewriting `SomeMailer.some_mail(ar_resource, 1234).deliver` to `SomeMailer.async_deliver.some_mail(ar_resource, 1234)`. Using ActiveRecord objects as arguments to mailers is still possible. This is achieved by storing the class name and the record id as arguments in the Resque queue which will be transformed back to records by the mailer job and passed along to the mailer.