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

RevObject's equals() was changed to be identity equals because two RevCommits parsed by two different RevWalk instances aren't exactly equal.  You cannot use one RevCommit in the other RevWalk... their object pools are different.

However I think this has turned out to be a non-issue.  Most developers are able to follow the rule of using only that RevWalk's RevObjects within the RevWalk that made them.  And if they don't, this different equals() implementation didn't help them to identify the problem.

Basically, I royally screwed this up ages ago when I created RevObject/RevWalk.  Its taken us years to realize it, and SAP to fix it.  I think the change makes sense, we should do it as part of 0.9, and applications that were depending on reference equality of RevObjects should use == and not .equals().