RFC 1521 and missing binary Content-Transfer-Encoding in email module

[Andy Leszczynski]

Why email/Encoders.py is missing binary encoding. It should be there
according to RFC 1521:

encoding := "Content-Transfer-Encoding" ":" mechanism
mechanism := "7bit" ; case-insensitive
/ "quoted-printable"
/ "base64"
/ "8bit"
/ "binary"
/ x-token

Would it be difficult to make it up?

A.