RFR: Add tags to subjects instead of replacing them

[Robin Westberg]

Hi all,

Please review this change that aims to make automated RFR reply subject rewrites a little bit less intrusive.

Best regards,
Robin

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

Commits:
 - 331a3cf0:	Tag subjects instead of replacing them

Pull request:
https://git.openjdk.java.net/skara/pull/131

Webrev:
https://webrevs.openjdk.java.net/skara/131/webrev.00

Patch:
https://git.openjdk.java.net/skara/pull/131.diff

Fetch command:
git fetch https://git.openjdk.java.net/skara pull/131/head:pull/131