Merge branch 'jh/notes' into next

Merge branch 'jh/notes' into next

* jh/notes: (30 commits)
  builtin-notes: Add "copy" subcommand for copying notes between objects
  builtin-notes: Misc. refactoring of argc and exit value handling
  builtin-notes: Add -c/-C options for reusing notes
  builtin-notes: Refactor handling of -F option to allow combining -m and -F
  builtin-notes: Deprecate the -m/-F options for "git notes edit"
  builtin-notes: Add "append" subcommand for appending to note objects
  builtin-notes: Add "add" subcommand for adding notes to objects
  builtin-notes: Add --message/--file aliases for -m/-F options
  builtin-notes: Add "list" subcommand for listing note objects
  Documentation: Generalize git-notes docs to 'objects' instead of 'commits'
  builtin-notes: Add "prune" subcommand for removing notes for missing objects
  Notes API: prune_notes(): Prune notes that belong to non-existing objects
  t3305: Verify that removing notes triggers automatic fanout consolidation
  builtin-notes: Add "remove" subcommand for removing existing notes
  Teach builtin-notes to remove empty notes
  Teach notes code to properly preserve non-notes in the notes tree
  t3305: Verify that adding many notes with git-notes triggers increased fanout
  t3301: Verify successful annotation of non-commits
  Builtin-ify git-notes
  Refactor notes concatenation into a flexible interface for combining notes
  ...

Conflicts:
	Makefile