there is no support for base64 mime-content-transfer-encoding support

[Adrian Vladu]

As reported here, Cloudbase-Init only supports raw mime parts: http://ask.cloudbase.it/question/2281/user_data-in-multipartmime-is-base64-encoded/

We need to implement full support for the RFC: https://www.w3.org/Protocols/rfc1341/5_Content-Transfer-Encoding.html

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/472649
Committed: https://git.openstack.org/cgit/openstack/cloudbase-init/commit/?id=2a5cd3a4120408f1baced5231da0eea246a3dffe
Submitter: Jenkins
Branch: master

commit 2a5cd3a4120408f1baced5231da0eea246a3dffe
Author: Paula Madalina Crismaru <email address hidden>
Date: Tue Jun 13 14:25:45 2017 +0300

    Adds support for all MIME Content-Transfer-Encodings

    According to [1], Content-Transfer-Encoding can have one of the
    following values (case insensitive): "BASE64" / "QUOTED-PRINTABLE" /
    "8BIT" / "7BIT" / "BINARY" / x-token.
    Values "8bit", "7bit", and "binary" all imply that NO encoding has been
    performed.
    "x-token" refers to a custom implementation that can be done, where the
    encoding agent and the decoding agent must agree upon. This case is not
    addressed by the patch.
    "QUOTED-PRINTABLE" and "base64" encodings are addressed by this patch,
    and the decoding is performed for all the multipart content types
    currently supported.

    [1]https://www.w3.org/Protocols/rfc1341/5_Content-Transfer-Encoding.html

    Change-Id: Iac29f3a287bd478f7f0b55d9911ae47f3a5890fb
    Closes-Bug: #1696420