Patch Set 1: Looks good to me, approved; IP review completed

I understand the desire to use text, but I think people notice their projects and files adorned more with a special icon (ie., the red conflict decoration) than a label. I opened a bug to consider this usability change in the future...

https://bugs.eclipse.org/318917

Also, how many different repository states are there? MERGE, REBASE and SAFE?