tests: add a test about evolve stabilizing orphan caused by splits There are some similar tests lying around in the test suite but they are not well arranged. I wanted the test suite to be a goto reference for all the behaviors till the time we get all of them documented.

test: fix output after rev-branch-cache has been merged Mercurial core 2090044a288d added a new revbranchcache part which changed some exchange-related outputs. Glob them to ease merging with old Mercurial versions branches.

cleanup: remove duplicate import of "obsolete"