teach bash completion to treat commands with "--" as a helper
teach bash completion to treat commands with "--" as a helper

There is a convention that commands containing a double-dash
are implementation details and not to be used by mortals. We
should automatically remove them from the completion
suggestions as such.

Signed-off-by: Jeff King <696e3fbcf235d40b6ea1ebd61c87cbea79d444e7@peff.net>
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