Merge branch 'jk/dumb-http-finalize'

Merge branch 'jk/dumb-http-finalize'

The dumb-http code regressed when the result of re-indexing a pack
yielded an *.idx file that differs in content from the *.idx file it
downloaded from the remote. This has been corrected by no longer
relying on the *.idx file we got from the remote.

* jk/dumb-http-finalize:
  packfile: use oidread() instead of hashcpy() to fill object_id
  packfile: use object_id in find_pack_entry_one()
  packfile: convert find_sha1_pack() to use object_id
  http-walker: use object_id instead of bare hash
  packfile: warn people away from parse_packed_git()
  packfile: drop sha1_pack_index_name()
  packfile: drop sha1_pack_name()
  packfile: drop has_pack_index()
  dumb-http: store downloaded pack idx as tempfile
  t5550: count fetches in "previously-fetched .idx" test
  midx: avoid duplicate packed_git entries