Fixed #6918, #12791: If an email message has an encoding, actually use that...

Fixed #6918, #12791: If an email message has an encoding, actually use that encoding to encode body and headers. Thanks for patch with tests oyvind.



git-svn-id: http://code.djangoproject.com/svn/django/trunk@12683 bcc190cf-cafb-0310-a4f2-bffc1f526a37