procmail: how to mime decode base64 + quoted printable

needs mimencode from the metamail package. (or equivalent).

# paranoia - backup
:0 c
backup

+########################################################+
# strip quoted-printable and base64 encoding
+########################################################+
:0
* ^Content-Type:.*text/plain
{
    :0 fbw
*** ^Content-Transfer-Encoding:.*base64
    | mimencode -u -b

    :0 fbw
*** ^Content-Transfer-Encoding:.*quoted-printable
    | mimencode -u -q
}