Add a hash function for OstreeRepo instances, which relies on the repo
being open, and hence being able to hash the device and inode of its
root directory.
Add unit tests for this and ostree_repo_equal().
Signed-off-by: Philip Withnall <withnall@endlessm.com>
https://github.com/ostreedev/ostree/issues/1191Closes: #1205
Approved by: cgwalters