chistedit: add option to show order of commits in opposite order Many users (including me) expect the order of commits in histedit to match the order in `hg log -G` and are confused because it doesnn't. This patch adds an option to show later commits first in the list. I've only added support for it in chistedit for now. As a consequence, I've marked the config option experimental (I think it should apply to both interfaces before it graduates). Differential Revision: https://phab.mercurial-scm.org/D11669