Introduce a new CHANGES format

git-svn-id: https://svn.apache.org/repos/asf/incubator/wave/branches/wave-0.4-release@1519051 13f79535-47bb-0310-9956-ffa450edef68
Some minor changes after previewing release

- Include THANKS in binary release
- Fold DISCLAIMER at 80
- Use Maven central rather than repo1/repo2

git-svn-id: https://svn.apache.org/repos/asf/incubator/wave/branches/wave-0.4-release@1519074 13f79535-47bb-0310-9956-ffa450edef68
Merge remote-tracking branch 'origin/wave-0.4-release' into wave-0.4-release