bug 452716: update CONTRIBUTING information

Change-Id: I62ab72b6d0f166d48c1c9f12a871d3664d17cb7a
Signed-off-by: Florian Thienel <florian@thienel.org>
bug 452716: enable bundle signing

Signed-off-by: Florian Thienel <florian@thienel.org>
bug 452716: update build job names

Signed-off-by: Florian Thienel <florian@thienel.org>
bug 452716: add about.html to all plug-ins

Signed-off-by: Florian Thienel <florian@thienel.org>
bug 452716: updated copyright years in features

Signed-off-by: Florian Thienel <florian@thienel.org>
Merge remote-tracking branch 'origin/master' into feature/newBoxModel