There are double frees and leaks around setup_revisions() API used
in "git stash show", which has been fixed, and setup_revisions()
API gained a wrapper to make it more ergonomic when using it with
strvec-manged argc/argv pairs.
* jk/setup-revisions-freefix:
revision: retain argv NULL invariant in setup_revisions()
treewide: pass strvecs around for setup_revisions_from_strvec()
treewide: use setup_revisions_from_strvec() when we have a strvec
revision: add wrapper to setup_revisions() from a strvec
revision: manage memory ownership of argv in setup_revisions()
stash: tell setup_revisions() to free our allocated strings