Do not use a naked "make", instead use TEST_MAKE. Now it fails differently.
Avoid
SyntaxError: Non-UTF-8 code starting with '\xb7' in file youtube-dl on line 3, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details

by installing the original unmodified file and a wrapper script.

I'm not sure why it broke or why this works better, but it does for me (TM).

Bump PKGREVISION.
Updated net/youtube-dl to 20140516.1nb1
Bah!  Don't bother installing rmail as it comes with the UUCP package
Updated mail/sendmail to 8.14.9nb3