Handle transactions!

Note: we can still deadlock on traversal vs transaction corner cases.
We handle transactions as single operation, which it logically is.

ccan/tdb/tools/tdbtorture.c

@@ -20,9 +20,9 @@
 #define DELETE_PROB 8
 #define STORE_PROB 4
 #define APPEND_PROB 6
-#if 0
 #define TRANSACTION_PROB 10
 #define TRANSACTION_PREPARE_PROB 2
+#if 0
 #define LOCKSTORE_PROB 5
 #endif
 #define TRAVERSE_PROB 20
@@ -144,6 +144,8 @@ static void addrec_db(void)
 		in_transaction--;
 		goto next;
 	}
+
+#if 0
 	if (in_traverse == 0 && in_transaction && random() % TRANSACTION_PROB == 0) {
 		if (tdb_transaction_cancel(db) != 0) {
 			fatal("tdb_transaction_cancel failed");
@@ -152,6 +154,7 @@ static void addrec_db(void)
 		goto next;
 	}
 #endif
+#endif
 
 #if REOPEN_PROB
 	if (in_traverse == 0 && in_transaction == 0 && random() % REOPEN_PROB == 0) {