Merge branch 'ps/object-source-management'

Code refactoring around object database sources.

* ps/object-source-management:
  odb: handle recreation of quarantine directories
  odb: handle changing a repository's commondir
  chdir-notify: add function to unregister listeners
  odb: handle initialization of sources in `odb_new()`
  http-push: stop setting up `the_repository` for each reference
  t/helper: stop setting up `the_repository` repeatedly
  builtin/index-pack: fix deferred fsck outside repos
  oidset: introduce `oidset_equal()`
  odb: move logic to disable ref updates into repo
  odb: refactor `odb_clear()` to `odb_free()`
  odb: adopt logic to close object databases
  setup: convert `set_git_dir()` to have file scope
  path: move `enter_repo()` into "setup.c"

diff --cc builtin/gc.c
Simple merge

diff --cc builtin/receive-pack.c
Simple merge

diff --cc fsck.c
Simple merge

diff --cc http-backend.c
Simple merge

diff --cc http-push.c
Simple merge

diff --cc midx-write.c
Simple merge

diff --cc packfile.c
Simple merge

diff --cc packfile.h
Simple merge

diff --cc refs.c
Simple merge

diff --cc setup.c
Simple merge