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

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/rpm2cpio.c b/archival/rpm2cpio.c
index 70021d5..ce8cd2c 100644
--- a/archival/rpm2cpio.c
+++ b/archival/rpm2cpio.c
@@ -7,7 +7,7 @@
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 #include "libbb.h"
-#include "unarchive.h"
+#include "archive.h"
 #include "rpm.h"
 
 enum { rpm_fd = STDIN_FILENO };