Merge branch 'js/detached-stash'

* js/detached-stash: t3903: fix broken test_must_fail calls detached-stash: update Documentation detached-stash: tests of git stash with stash-like arguments detached-stash: simplify git stash show detached-stash: simplify git stash branch detached-stash: refactor git stash pop implementation detached-stash: simplify stash_drop detached-stash: simplify stash_apply detached-stash: work around git rev-parse failure to detect bad log refs detached-stash: introduce parse_flags_and_revs function