tests: various comment on test-evolve-phase-divergence

tests: make test-evolve-phase-divergence more descriptive This patch adds description to what each part is doing in test-evolve-phase-divergence.t and some commands which should be used to analyze the divergence before resolving that.

compat: use updateresult API if available The status return is no longer a tuple, we access attribute instead.

compat: provide an explicit default value to the 'odiff' config There is a devel warning about this now.

compat: keep passing arguments as keyword argument Otherwise, This break with new changes in upstream Mercurial.

compat: search for stringmatcher in the new location More of util has been split into sub modules.

rebase: update the rebase wrapping to works with hg 4.6 Mercurial core commit bd0086bd3af4 removed _makeextrafn hence breaking our wrapping. Update the code to wrap rebaseruntime directly in a way that's compatible with hg 4.1+.

compat: call current obsolete.createmarkers(), not one from load time Other extensions may wrap obsolete.createmarkers(). If they do, we should call their wrapped version. However, since f61a23a84dac (compat: add wrapper for obsolete.createmarkers() that accepts "operation" arg, 2018-03-16), we started storing the version of the function as it was when our compat module was loaded. This broke an extension we use internally at Google.

tests: rename test-evolve-bumped to test-evolve-phase-divergence.t While I was here, I added a heading to test mentioning what the test if for.

evolve: replace bumped in function name to phasedivergence bumped was the old name of phasedivergence. Lets replace with its new name so that we can forget the old one.