Prettify log decorations even more

"tag: v1.6.2.5" looks much better than "tag: refs/tags/v1.6.2.5".

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

log-tree.c

@@ -25,6 +25,7 @@ static int add_ref_decoration(const char *refname, const unsigned char *sha1, in
 	struct object *obj = parse_object(sha1);
 	if (!obj)
 		return 0;
+	refname = prettify_refname(refname);
 	add_name_decoration("", refname, obj);
 	while (obj->type == OBJ_TAG) {
 		obj = ((struct tag *)obj)->tagged;

t/t4013/diff.log_--decorate_--all

@@ -1,12 +1,12 @@
 $ git log --decorate --all
-commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (refs/heads/master)
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (master)
 Merge: 9a6d494 c7a2ab9
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:04:00 2006 +0000
 
     Merge branch 'side'
 
-commit c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a (refs/heads/side)
+commit c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a (side)
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:03:00 2006 +0000
 
@@ -26,7 +26,7 @@ Date:   Mon Jun 26 00:01:00 2006 +0000
     
     This is the second commit.
 
-commit 444ac553ac7612cc88969031b02b3767fb8a353a (refs/heads/initial)
+commit 444ac553ac7612cc88969031b02b3767fb8a353a (initial)
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:00:00 2006 +0000