RFR: Try adapting to malformed mboxes

[Robin Westberg via github.com]

Hi all,

Please review this change that tries to handle malformed mbox files, where lines start with `From ` without being an actual message break. If the lines following the `From ` cannot be parsed as an email, append it to the previous message and try again.

Best regards,
Robin

----------------

Commits:
 - c53c58c2:	Fix trailing whitespace
 - 15969c85:	Try adapting to malformed mboxes

Pull request:
https://git.openjdk.java.net/skara/pull/91

Webrev:
https://webrevs.openjdk.java.net/skara/91/webrev.00

Patch:
https://git.openjdk.java.net/skara/pull/91.diff

Fetch command:
git fetch https://git.openjdk.java.net/skara pull/91/head:pull/91