447637: MailUtility: add support for adding attachments to existing mime
messages 

Change-Id: Iaba7c9960e231a8ffd3fc69dc877bec93d1d78e7
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=447637
Reviewed-on: https://git.eclipse.org/r/35466
Tested-by: Hudson CI
Reviewed-by: Christoph Schwank <christoph.schwank@bsiag.com>
448638: HtmlUtility.cleanupCss throws
java.util.ConcurrentModificationException

Change-Id: I4623957fa711a20bd2d913f43eaf5da6f77c6a52
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=448638
Reviewed-on: https://git.eclipse.org/r/35474
Tested-by: Hudson CI
Reviewed-by: Christoph Schwank <christoph.schwank@bsiag.com>