Fix for matches_dynamic_method? on ActionMailer

The attached patch fixes this and makes Action::Mailer.method_missing just catch methods which begin with create and deliver

Well spotted! I have a couple of enhancements to the patch that could be made.

1. match = matches_dynamic_method?(method_symbol) looks clearly broken as of 3cf773b. This should be fixed separately, possibly in a separate commit, with another failing testcase (ex1 is a fairly ugly way of doing this).
2. Commit notes should be referring to Prefix not Suffix ;)
3. Having two else conditions with calls to super in a row does not scan well. How about using (ex2) at the top? It also gets rid of a layer of nesting, which is nice.

ex1:

  def test_should_still_raise_exception_with_expected_message_when_calling_an_undefined_method
    begin
      RespondToMailer.not_a_method
      fail("Expected a NoMethodError.")
    rescue NoMethodError => e
      assert_match(/undefined method.*not_a_method/, e.message)
    rescue Exception => e
      fail("Expected a NoMethodError, got #{e.class}.")
    end
  end

ex2:

return super unless match = matches_dynamic_method?(method_symbol)

+1 Joel, Tom - Thanks for fixing my original commit and sorry for introducing the bug. Cheers, James.