Forwardable with hash and instance variable extensions

 Provides more Forwardable methods for your source as
 Forwardable::Extended.
 .
  - Any delegation can accept `alias_of' which will be the message sent
    to the object.
  - You can send arguments by attaching the keyword `:args => [:my_arg]',
    these are sent a `#to_s message.'
  - Any delegation can be boolean if you wish it to be, even `:reverse'.