Convert the remaining functions to take pointers to struct object_id
instead of pointers to unsigned char, and update the internals of these
functions as well. Among these functions is a caller of lookup_tag,
which we will convert shortly.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>