rewind: add a test for rewinding a split There are no code change needed but it is worth testing on its own.

rewind: update the working copy if it gets obsoleted If the working copy parent is rewinded, follow the rewind.

rewind: add a message about obsolete changeset Not the best output, but useful to have the data. We can improve that later.

rewind: obsolete latest successors unless instructed otherwise To prevent the creations of divergence, we automatically mark the successors set of the rewinded changeset as obsoleted by the rewind result. A new flag `--as-divergence` is added to disable this behavior.

rewind: test rewinding an amended changesets We are now able to rewind a simple amended changeset. For now, its current successors has not been obsoleted and we created divergence.

rewind: add a message about the rewinded changesets This helps to understand what happened.

rewind: add a proto version of the command This first version focus on rewinding a single revision without care for the consequence.

stablesort: make sure heads are processed in sorted order changeset 72621094505f will fix some ordering issue in the `heads` revset so we stabilise the output in advance.

evolve: move the bookmarks also when updating to successor (issue5923) When we are on an obsolete node and does `hg evolve`, it updates to it's sucessor, however it does not move the bookmark to the successor. This patch adds logic to make sure we move the bookmark too. Test change demonstrates the fix.

tests: add test to demonstrate issue5923 This will be fixed in upcoming patch.