If somebody wants to only know on-disk footprint of an object
without having to know its type or payload size, we can bypass a
lot of code to cheaply learn it.

* jk/cat-file-batch-optim:
  Fix some sparse warnings
  sha1_object_info_extended: pass object_info to helpers
  sha1_object_info_extended: make type calculation optional
  packed_object_info: make type lookup optional
  packed_object_info: hoist delta type resolution to helper
  sha1_loose_object_info: make type lookup optional
  sha1_object_info_extended: rename "status" to "type"
  cat-file: disable object/refname ambiguity check for batch mode