This has a very basic level of functionality (deltas can be generated,
and applied offline). There is only some stubbed out pull code to
fetch them via HTTP.
But, better to commit this now and improve it from a known starting
point, rather than have it languish in a branch.
Add an optional dependency on gpgme to add GPG signatures into the
detached metadata, with the key "ostree.gpgsigs", as an "aay", an
array of signatures (treated as binary data).
The commit command gains a --gpg-sign=<key-id> argument. Also add an
argument --gpg-homedir to set the GPG homedir where we look for
keyrings.
We used to have a version of this, but since I'm trying to use
GBytes more, this became a more common operation, and it's annoying
to type out the whole G_VARIANT_TYPE ("ay") each time, and pass
TRUE for trusted.
https://bugzilla.gnome.org/show_bug.cgi?id=706031
Having the archived vs not distinction in the object system wasn't
useful in light of pack files. In fact, we should probably move
towards generating a pack file per commit by default.