Initial code drop for merging block_cache

thin-provisioning/thin_delta.cc

@@ -72,7 +72,7 @@ namespace {
 	block_manager<>::ptr
 	open_bm(string const &path) {
 		block_address nr_blocks = get_nr_blocks(path);
-		block_io<>::mode m = block_io<>::READ_ONLY;
+		block_manager<>::mode m = block_manager<>::READ_ONLY;
 		return block_manager<>::ptr(new block_manager<>(path, nr_blocks, 1, m));
 	}