rust: Make some file path parameters less generic These are not widely used APIs that benefit from being maximally flexible, taking an explicit `&Path` borrow is fine and simplifies their internals. Differential Revision: https://phab.mercurial-scm.org/D10833

convert-bazaar: use breezy package instead of old bzr one Breezy is the most recent of the two, and works on Python 3 while being compatible with the (old) Bazaar file format. This patch contains a variety of unicode <-> bytes changes, API breakage fixing, restoring failing imports and changing the executable from `bzr` to `brz`. I recommend using the debian packages for `brz` and `python3-breezy` (3.1+), because the pip package seems to be haunted by radioactive dragons. Differential Revision: https://phab.mercurial-scm.org/D10513

bzr: only support bzr conversion on Python3 Python 2 support will be dropped from Mercurial before anyone needs to do a bzr -> hg conversion on Python 2 again. Bazaar tests were broken with the new lib anyway, which we'll get into in the next patches. Differential Revision: https://phab.mercurial-scm.org/D10512

rewriteutil: add pointer to help text when rewrite would cause divergence The evolve extension's version of the hint has this pointer. I missed it when I moved it to core. This is pretty much the same as D10723. Turns out I missed two places :( Differential Revision: https://phab.mercurial-scm.org/D10832

rhg: Add support for dirstate-v2 Differential Revision: https://phab.mercurial-scm.org/D10804

rhg: Remove some intermediate Vecs in `rhg files` Instead of calling `parse_dirstate` which then calls `parse_dirstate_entries`, call the latter directly in order to skip some intermediate steps. Differential Revision: https://phab.mercurial-scm.org/D10803

merge: make applyupdates() not mutate mresult argument We have an extension at work that overrides `merge.applyupdates()` to make it skip some writes and instead instruct the virtual filesystem we use to get a different version. That override doesn't work correctly when doing `hg co -m` and there's a modified file in the dirstate that's deleted in the destination. That's because `applyupdates()` mutates its `mresult` argument and our extension had passed in a modified copied of `mresult` to the overridden function, which resulted in the mutation not having any effect. This patch fixes that by letting the caller (i.e. `merge._update()`) update `mresult` with the extra actions instead. Besides fixing our internal extension, that seems cleaner to me anyway (better to not mutate `mresult` only in some cases and we can skip some of the logic if we're not going to update the dirstate anyway). Differential Revision: https://phab.mercurial-scm.org/D10830

index: use an explicit constant for INDEX_HEADER format and use it for docket This avoid leaking python-3.6 compatibility details too much. Differential Revision: https://phab.mercurial-scm.org/D10831