UTF-8 emails

[Olav Vitters <olav vitters nl>]

I've changed the commits-list emails and the ftp-release-list emails to
correctly show utf-8.

In practice:
 * generate the right From: header for UTF-8 names
 * set MIME-encoding for commits-list emails
   The script does NOT check if the diff actually has UTF-8 (difficult
   to do).

See e.g.
https://mail.gnome.org/archives/ftp-release-list/2011-June/thread.html

for the impact (Tim-Philipp Müller vs Chris Kühl)
-- 
Regards,
Olav