hbisect: use a revset for ancestor calculation Since we have revsets we can be more concise in doing the ancestor calulcation. Significant commits are all descendent of the topmost good commits. Test Plan: python run-tests.py test-bisect* Differential Revision: https://phab.mercurial-scm.org/D1498

hbisect: pass repo into hbisect.bisect Pass repo into the bisect function to get more flexibility in what we can call. This will allow us to use revsets to rewrite parts of the ancestor and children calculation in later patches. Test Plan: python run-tests.py test-bisect* Differential Revision: https://phab.mercurial-scm.org/D1497

develwarn: do not emit warning if "config" is unspecified Previously, if the develwarn call site did not specify the category of warning, and devel.all-warnings was False, it would emit the warning. If it was intended that this emit a warning if config is unspecified, I would have expected a comment, so I assumed this was unintentional and am changing the behavior. Differential Revision: https://phab.mercurial-scm.org/D1494