rebase: add --stop option to stop rebase at any point (issue5206) Before this patch, during a rebase if you get a point where you can't figure out what to do next, then either you had to complete your series or abandon all the work you have done during this rebase. Now, with this feature you can stop at any point by keeping the rebased csets and mark original csets as obsolete. And if you don't have evolution extension enabled then you can use --keep option as an alternative which will keep original csets too, instead of marking them obsolete. Differential Revision: https://phab.mercurial-scm.org/D3959