Merge branch 'jt/unify-object-info'

Code clean-ups.

* jt/unify-object-info:
sha1_file: refactor has_sha1_file_with_flags
sha1_file: do not access pack if unneeded
sha1_file: teach sha1_object_info_extended more flags
sha1_file: refactor read_object
sha1_file: move delta base cache code up
sha1_file: rename LOOKUP_REPLACE_OBJECT
sha1_file: rename LOOKUP_UNKNOWN_OBJECT
sha1_file: teach packed_object_info about typename

diff --cc builtin/cat-file.c
Simple merge

diff --cc builtin/fetch.c
Simple merge

diff --cc builtin/index-pack.c
Simple merge

diff --cc cache.h
Simple merge

diff --cc sha1_file.c
Simple merge