Merge branch 'bc/object-id'

More transition from "unsigned char[40]" to "struct object_id". This needed a few merge fixups, but is mostly disentangled from other topics. * bc/object-id: remote: convert functions to struct object_id Remove get_object_hash. Convert struct object to object_id Add several uses of get_object_hash. object: introduce get_object_hash macro. ref_newer: convert to use struct object_id push_refs_with_export: convert to struct object_id get_remote_heads: convert to struct object_id parse_fetch: convert to use struct object_id add_sought_entry_mem: convert to struct object_id Convert struct ref to use object_id. sha1_file: introduce has_object_file helper.