cmdutil: add a kludge to make bytes repr() the same on 2 and 3 This fixes the output formatting problems I see in debugobsolete. I still am seeing some effectflag differences, which we'll need to tackle separately. I'm not in love with this approach. There might be something better we could do, and I'd love it if someone else wanted to take a run at this. Differential Revision: https://phab.mercurial-scm.org/D1909