add_ref(): take a (struct ref_entry *) parameter
add_ref(): take a (struct ref_entry *) parameter

Take a pointer to the ref_entry to add to the array, rather than
creating the ref_entry within the function.  This opens the way to
having multiple kinds of ref_entries.

Signed-off-by: Michael Haggerty <c24c152f145c57791e809b126db9e61bd1c1782d@alum.mit.edu>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git