update revset vocabulary to use precursors, successors

obsolete: remove unused variable in rebase wrapping

evolve: tidy up a bit - long lines - extra blank lines - commands options descriptions

obsolete: make collapse create less markers Collapsing A and B into C was registering: A -> C B -> C A -> B At this point, the last relation brings nothing and is removed for the sake of simplicity: A -> C B -> C test-evolve.t is slightly modified as one of the relations let stabilize compute a target outside of the parent revision tree. This is a stabilize bug, not trivial to fix, so let's tweak the test for now.

obsolete: remove unused code from reposetup()

obsolete: suspended changeset with secret only children should be secret too test-obsolete-push.t: exhibit outgoing bug with suspended changeset in this case

obsolete: add 'obsolete' keyword The obsolete keyword displays the node status among 'stable', 'unstable', 'suspended', 'extinct'.

obsolete: unify collapsed revisions markers handling When collapsing A, B and C into D, amend was registering: A -> D B -> D A -> B C -> D A -> C while the rebase wrapper was doing: A -> D B -> D C -> D At this point, I have no argument to favor one or another or even a new one like: A -> B B -> C C -> D so I am aligning the rebase implementation on the older amend one. At least we can now change them all at once.

rebase: improve invalid revisions filtering - Filter rebasestate nullmerge and unrebased revision before considering updating obsolete. This simplifies the handling of obsolete and make it ignore unrebased revision rather than extinguishing them. - Apply obsolete markers only if rebasestate is not empty, testing rebasetarget was irrelevant.

test-evolve: extend output and exhibit an amend bug The extended section shows the parent revision stabilizing itself on another revision, without --any. In theory, only descendants of the parent predecessors or of its descendants should be stabilized, and be stabilized in parent subtree. Unfortunately, stabilize implementation correctly picks the changesets to stabilize but not their target. This problem is aggravated by amend registering too many obsolete markers which prevents the stabilize selection heuristic to prune several changesets.