[RFC/PATCH 0/8] Untracked cache improvements

Following the discussions on the "config: add core.trustmtime" patch I previously sent, here is a patch series that tries to improve the untracked cache feature.

This patch series implements core.untrackedCache instead of core.trustmtime. core.untrackedCache is more complex because basically when it's set to true git should always try to use the untracked cache, and when set to false git should never use it.

Patchs 1/8 and 2/8 add some features that are missing. Patchs 3/8, 4/8 and 5/8 are some refactoring to prepare for patch 6/8 which implements core.untrackedCache.

Up to patch 6/8 backward compatibility is preserved. Patchs 7/8 and 8/8 are trying to improve usability by making the untracked cache cli and config options more in line with other git cli and config options, but this sacrifies some backward compatibility.

Christian Couder (8):
  update-index: add untracked cache notifications
  update-index: add --test-untracked-cache
  update-index: move 'uc' var declaration
  dir: add add_untracked_cache()
  dir: add remove_untracked_cache()
  config: add core.untrackedCache
  update-index: prevent --untracked-cache from performing tests
  update-index: make core.untrackedCache a bool

 Documentation/config.txt               | 10 +++++++++
 Documentation/git-update-index.txt     | 30 +++++++++++++++++++-------
 builtin/update-index.c                 | 39 ++++++++++++++++------------------
 cache.h                                |  1 +
 config.c                               |  4 ++++
 contrib/completion/git-completion.bash |  1 +
 dir.c                                  | 22 ++++++++++++++++++-
 dir.h                                  |  2 ++
 environment.c                          |  1 +
 t/t7063-status-untracked-cache.sh      |  2 +-
 wt-status.c                            |  9 ++++++++
 11 files changed, 90 insertions(+), 31 deletions(-)