Objects does not need to be separated by `local` and `remotes`, it
uses `iter` internally, so all references are used regardless.
Simplify Objects by having it be a simple vector of references.
This also means that the `identifier` is not needed. This was only
required to identify the local reference, so it can now be removed.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
0bd213d15a