Merge branch 'ps/history' into seen

"git history" history rewriting UI.

* ps/history:
  builtin/history: implement "split" subcommand
  cache-tree: allow writing in-memory index as tree
  add-patch: add support for in-memory index patching
  add-patch: remove dependency on "add-interactive" subsystem
  add-patch: split out `struct interactive_options`
  add-patch: split out header from "add-interactive.h"
  builtin/history: implement "reword" subcommand
  builtin: add new "history" command
  replay: parse commits before dereferencing them
  replay: stop using `the_repository`
  replay: extract logic to pick commits
  wt-status: provide function to expose status for trees

diff --cc .gitignore
Simple merge

diff --cc Documentation/meson.build
Simple merge

diff --cc Makefile
Simple merge

diff --cc add-interactive.c
Simple merge

diff --cc add-patch.c
Simple merge

diff --cc builtin/add.c
Simple merge

diff --cc cache-tree.c
Simple merge

diff --cc git.c
Simple merge

diff --cc meson.build
Simple merge

diff --cc t/meson.build
Simple merge