- tools::as_singlepart() was moved to internal function Sympa::Message::_as_singlepart().
- New method Sympa::Message::get_plain_body() to get decoded content of plain/text part.
- tools::decode_header() was renamed to Sympa::Message::get_decoded_header() and it became taking only Sympa::Message instance as argument.


git-svn-id: https://subversion.renater.fr/sympa/branches/sympa-6.2-branch@11350 05aa8bb8-cd2b-0410-b1d7-8918dfa770ce