Merge branch 'mk/maint-parse-careful'

* mk/maint-parse-careful:
  receive-pack: use strict mode for unpacking objects
  index-pack: introduce checking mode
  unpack-objects: prevent writing of inconsistent objects
  unpack-object: cache for non written objects
  add common fsck error printing function
  builtin-fsck: move common object checking code to fsck.c
  builtin-fsck: reports missing parent commits
  Remove unused object-ref code
  builtin-fsck: move away from object-refs to fsck_walk
  add generic, type aware object chain walker

Conflicts:

	Makefile
	builtin-fsck.c

cache.h

@@ -274,6 +274,7 @@ enum object_type {
 	/* 5 for future expansion */
 	OBJ_OFS_DELTA = 6,
 	OBJ_REF_DELTA = 7,
+	OBJ_ANY,
 	OBJ_MAX,
 };