shell prompt: add bash.showUntrackedFiles option
shell prompt: add bash.showUntrackedFiles option

Add a config option 'bash.showUntrackedFiles' which allows enabling
the prompt showing untracked files on a per-repository basis. This is
useful for some repositories where the 'git ls-files ...' command may
take a long time.

Signed-off-by: Martin Erik Werner <f1bdc424ffcfdeb5aeb2aebae202480d3984cbaf@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git