We have a bunch of APIs to do GPG verification of a commit,
but that doesn't generalize to signapi. Further, they
require the caller to check the signature status explicitly
which seems like a trap.
This much higher level API works with both GPG and signapi.
The intention is to use this in things that are doing "external
pulls" like the ostree-ext tar import support. There we will
get the commitmeta from the tarball and we want to verify it
at the same time we import the commit.
Luca BRUNO
Colin Walters