* cc/bisect:
Bisect reset: do nothing when not bisecting.
Bisect: use "$GIT_DIR/BISECT_NAMES" to check if we are bisecting.
Bisect visualize: use "for-each-ref" to list all good refs.
git-bisect: modernize branch shuffling hack
git-bisect: use update-ref to mark good/bad commits
git-bisect: war on "sed"
Bisect reset: remove bisect refs that may have been packed.