mikel/mail — pull request #308 by kennyj (2011-12-07 11:12:37+00:00)
Title: Fix non-ascii character folding problem (rails issue 3824)

In the present spec,
when the folding, an ascii only character line is not encoded.

But the ascii only line, that in the subject included non ascii character, must be encoded.
For example, gmail's behavior is that lines with non ascii character is encoded.

Please see also https://github.com/rails/rails/issues/3824 .