Merge branch 'master' of git://git.kernel.org/pub/scm/git/git

Merge branch 'master' of git://git./git/git

* 'master' of git://git.kernel.org/pub/scm/git/git: (23 commits)
  Allow fast-import frontends to reload the marks table
  Use atomic updates to the fast-import mark file
  Teach receive-pack to run pre-receive/post-receive hooks
  Refactor handling of error_string in receive-pack
  Refactor run_update_hook to be more useful
  Don't run post-update hook unless a ref changed
  Move post-update hook to after all other activity
  Preallocate memory earlier in fast-import
  Cast 64 bit off_t to 32 bit size_t
  Use off_t in pack-objects/fast-import when we mean an offset
  Use off_t when we really mean a file offset.
  Use uint32_t for pack-objects counters.
  Use uint32_t for all packed object counts.
  General const correctness fixes
  Don't build external_grep if its not used
  Fix mmap leak caused by reading bad indexes.
  Display the null SHA-1 as the base for an OBJ_OFS_DELTA.
  git-archimport: allow remapping branch names
  t/t5515-fetch-merge-logic.sh: Add two more tests
  Catch write_ref_sha1 failure in receive-pack
  ...