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

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/read_printf.c b/libbb/read_printf.c
index 7ca3d68..8664bc6 100644
--- a/libbb/read_printf.c
+++ b/libbb/read_printf.c
@@ -15,7 +15,7 @@
 )
 
 #if ZIPPED
-# include "unarchive.h"
+# include "archive.h"
 #endif