[1.1.X] Fixed #11144 -- When a to/from/cc header contains unicode, make sure...

[1.1.X] Fixed #11144 -- When a to/from/cc header contains unicode, make sure the email addresses are parsed correctly (especially with regards to commas). Thanks to rmt for the patch.

Backport of r11719 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@11720 bcc190cf-cafb-0310-a4f2-bffc1f526a37