Body of send emails is mail_mail.body_html, not body anymore.
Signature adding is back to mail_followers.notify().
Subject adding is still done just before sending.
Updated mail_mail view. mail.compose.message: body_text inside <pre>.
[TESTS] mail: added tests for message_post, updated tests for mail.message.compose to test the composer only.
bzr revid: tde@openerp.com-20120830085116-o5h13yqodt0vof0k