rename archival/libunarchive -> archival/libarchive; move bz/ into it

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

archival/libarchive/header_list.c

@@ -0,0 +1,12 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+#include "libbb.h"
+#include "archive.h"
+
+void FAST_FUNC header_list(const file_header_t *file_header)
+{
+//TODO: cpio -vp DIR should output "DIR/NAME", not just "NAME" */
+	puts(file_header->name);
+}