Fix regression introduced by 25b5e0f (checkout & stash callbacks) in which custom checkout options weren't passed to git_stash_apply and git_stash_pop.
This PR also adds a unit test to ensure custom checkout options are honored during a stash apply or pop.
Fix regression introduced by 25b5e0f (checkout & stash callbacks) in which custom checkout options weren't passed to git_stash_apply and git_stash_pop.
This PR also adds a unit test to ensure custom checkout options are honored during a stash apply or pop.