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

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

archival/libarchive/get_header_tar_bz2.c

@@ -0,0 +1,21 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+#include "libbb.h"
+#include "archive.h"
+
+char FAST_FUNC get_header_tar_bz2(archive_handle_t *archive_handle)
+{
+	/* Can't lseek over pipes */
+	archive_handle->seek = seek_by_read;
+
+	open_transformer(archive_handle->src_fd, unpack_bz2_stream_prime, "bunzip2");
+	archive_handle->offset = 0;
+	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
+		continue;
+
+	/* Can only do one file at a time */
+	return EXIT_FAILURE;
+}