prepare version 5.1.2

merge with default there is some 3.6 related fix and test change that we need on default. No other significant change happened since last release expect for split, still marked experimental. So we prepare for a bugfix release.

split: mark the command as experimental It has a bit too many rough edge for now.

tests: run test with 3.6 and apply test change Tested with 3.4, 3.5 and 3.6. Some minor test update had to be done.

prune: have dirstate collaborate with transaction With 3.6, dirstate update can work with transaction to ensure proper rollback. We do it if the mercurial version permit it.

evolve: have dirstate collaborate with transaction With 3.6, dirstate update can work with transaction to ensure proper rollback. We do it if the mercurial version permit it.

prune: reuse revset from repair instead of copy-pasting code

merge with stable

evolve: compatibility with coming 3.6 Some function in the import stack changed, we have to adapt.

evolve: be more complete about copying extra from old revisions For 'hg evolve' we want to copy all extra-level metadata except for branch. This keeps the experimental topics extension from getting obliterated by evolve runs. Many hashes in tests changed due to some extra data coming along for the ride in various places, but no functionality that was tested. It's plausible that this copies too much metadata - maybe we should be dropping rebase_src or convert_revision as well. Right now no tools do that, so I'm biasing towards preserving everything except branch when copying metadata for now.