Merge branch 'ar/config-hook-cleanups'

Code clean-up around the recent "hooks defined in config" topic.

* ar/config-hook-cleanups:
  hook: reject unknown hook names in git-hook(1)
  hook: show disabled hooks in "git hook list"
  hook: show config scope in git hook list
  hook: introduce hook_config_cache_entry for per-hook data
  t1800: add test to verify hook execution ordering
  hook: make consistent use of friendly-name in docs
  hook: replace hook_list_clear() -> string_list_clear_func()
  hook: detect & emit two more bugs
  hook: rename cb_data_free/alloc -> hook_data_free/alloc
  hook: fix minor style issues
  builtin/receive-pack: properly init receive_hook strbuf
  hook: move unsorted_string_list_remove() to string-list.[ch]

diff --cc Makefile
Simple merge

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

diff --cc refs.c
Simple merge

diff --cc transport.c
Simple merge