[Zope] change to MimeWriter to add "MIME-Version: 1.0"

[Pate, Clarence T]

If anyone is interested in the "MIME-Version header", I have played with the
mime stuff and read rfc1341 to understand better how this stuff works.  I am
enclosing a subset of MimeWriter.py which will allow the functions to put the
"MIME-Version: 1.0" header in the correct place.  I would like to warn everyone
that I am not a python programmer, and there might be a better way to do this.

The changed subset:

    def startbody(self, ctype, plist=[], prefix=1, version=0):
        for name, value in plist:
            ctype = ctype + ';\n %s=\"%s\"' % (name, value)
        self.addheader("Content-Type", ctype, prefix=prefix)
        if version:
            self.addheader("MIME-Version", "1.0", prefix=1)
        self.flushheaders()
        self._fp.write("\n")
        return self._fp

    def startmultipartbody(self, subtype, boundary=None, plist=[], prefix=1):
        self._boundary = boundary or mimetools.choose_boundary()
        return self.startbody("multipart/" + subtype,
                              [("boundary", self._boundary)] + plist,
                              prefix=prefix, version=1)


This will only place the "MIME-Version: 1.0" header if you are using the
<!--#mime --> tag.  This sends a multipart/mixed message.

Clarence T. Pate