merge with some older backport

template: add a troubles keyword This keyword list all evolution troubles that affect a changeset. Evolution troubles can be "unstable", "divergent" and "bumped".

evolve: make fold aware of allowunstable Before this patch, the fold command was performing the same way regardless of the value of experimental.evolution. With this patch if the configuration does not allow unstability, fold won't create instability.

evolve: make prune respect allowunsable Before this patch, the prune command was performing the same way regardless of the value of experimental.evolution. With this patch if the configuration does not allow unstability, prune won't create instability.

merge with stable

evolve: add a hint about how to abort an evolve with conflict The whole evolve --continue is hacky, but the way to abort it have been arcane knowledge, carried from sith lord to its apprentice for centuries. We add a hint to help the use discover it. One day a clean solution will come.

merge with branch closing commit

close 3.1 compat branch

evolve: marks the extension as tested with 4.1 Because it is.

merge with stable

evolve: fix default value for --confirm Before this changes, the default was yes, unlike advertised. The test were actually catching that so I go them updated.

prune: use the bookmark wrapper for 3.4 compatibility

merge with stable

evolve: update readme regarding the preview perf improvement

evolve: move 'allsuccessors()' to smarted usage The "new" smarted can be significantly more efficient than the old was. We convert our revset to take advantage of that.