rebase: remove revprecursor and revpruned states (BC) Those states are no longer necessary for rebase to function properly. Remove them to make the code cleaner. Marked as BC because in a corner case where working parent is obsoleted, and is skipped for rebase, we no longer move working parent after rebase completes. That is better since if working parent is obsoleted, it should be the user moving working parent back there (after a rebase) explicitly, in that case, we shouldn't move working parent again. Differential Revision: https://phab.mercurial-scm.org/D24

rebase: move obsoleted not rebased messages earlier (BC) A later patch will clean up those states. This patch moves the messages earlier. Marked as BC since the order of message has changed. Differential Revision: https://phab.mercurial-scm.org/D23

rebase: extract ctx description logic to a function The function will be used in a later patch. Differential Revision: https://phab.mercurial-scm.org/D22