Simplify is_kept_pack()

This removes --unpacked=<packfile> parameter from the revision parser, and
rewrites its use in git-repack to pass a single --kept-pack-only option
instead.

The new --kept-pack-only option means just that.  When this option is
given, is_kept_pack() that used to say "not on the --unpacked=<packfile>
list" now says "the packfile has corresponding .keep file".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/revision.h b/revision.h
index af414e5..f63596f 100644
--- a/revision.h
+++ b/revision.h
@@ -47,7 +47,8 @@
 			blob_objects:1,
 			edge_hint:1,
 			limited:1,
-			unpacked:1, /* see also ignore_packed below */
+			unpacked:1,
+			kept_pack_only:1,
 			boundary:2,
 			left_right:1,
 			rewrite_parents:1,
@@ -75,9 +76,6 @@
 			missing_newline:1;
 	enum date_mode date_mode;
 
-	const char **ignore_packed; /* pretend objects in these are unpacked */
-	int num_ignore_packed;
-
 	unsigned int	abbrev;
 	enum cmit_fmt	commit_format;
 	struct log_info *loginfo;
@@ -159,6 +157,6 @@
 extern enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit);
 
 extern int has_sha1_kept_pack(const unsigned char *sha1, const struct rev_info *);
-extern int is_kept_pack(const struct packed_git *, const struct rev_info *);
+extern int is_kept_pack(const struct packed_git *);
 
 #endif