config: add --source option to include source of value Showing the source of each config option is quite useful and not something the user should have to reach for the `--debug` flag for. I updates documentation and tests, except for one place in `test-hgrc.t` where I thought the test might have been intended to also test that `--debug` results in `ui.quiet` etc being test. Differential Revision: https://phab.mercurial-scm.org/D10668

rewriteutil: say how many commits would become orphan if commit is rewritten This copies the message from the evolve extension, but modifies it a bit to work with the grammar (in particular with the use of "change branch of" as `action`). I don't know why it doesn't use the same `_formatrevs()` as for public commmits. Differential Revision: https://phab.mercurial-scm.org/D10671

rewriteutil: give examples of public changesets that can't be rewritten This patch copies the feature from the evolve extension. Differential Revision: https://phab.mercurial-scm.org/D10670

convert: update p4 for Python 3 Differential Revision: https://phab.mercurial-scm.org/D10703

tests: change the fixer commands to use the buffer attribute on stdio objects Otherwise `\r` was getting injected into the fixed lines and throwing off the commit hashes on Windows when the fixer is invoked with py3. Differential Revision: https://phab.mercurial-scm.org/D10637

tests: stabilize test-persistent-nodemap.t on Windows Several issues here: - Hooks can't invoke shell scripts on Windows, so use `sh` to launch - `dd` in MSYS only recognizes `status=noxfer` - The `PATH` updating triggered a massive slowdown, but is no longer needed I have no idea why, but removing the `PATH` update substantially increased the speed of the test. It was running finishing at ~4:30 with `--debug` and ~14:50 without it, but now completes in ~2:20 on my Windows laptop. Differential Revision: https://phab.mercurial-scm.org/D10636