DATACASS-575 - Support IF conditions in lightweight transactions with UPDATE and DELETE.

We now support conditions in lightweight transactions for UPDATE and DELETE statements. Conditions are Filter objects similar to the WHERE clause. Conditions are supported for entity and query-based update/delete methods.

UpdateOptions options = UpdateOptions.builder().ifCondition(where("firstname").is("Walter")).build();
User user = new User("heisenberg", "Walter", "White");
template.update(user, options);

DeleteOptions options = DeleteOptions.builder().ifCondition(where("counter").is(42)).build();
Query query = Query.query(where("id").is("heisenberg")).queryOptions(options);
template.delete(query, User.class);

src/main/asciidoc/new-features.adoc

@@ -8,6 +8,8 @@ This chapter summarizes changes and new features for each release.
 * Read-only properties annotated with `@ReadOnlyProperty` to exclude non-writable properties from entity-bound `INSERT` and `UPDATE` operations.
 * Support for derived `Between` queries.
 * Kotlin Coroutine extensions for `ReactiveFluentCassandraOperations`.
+* Lightweight transaction support via `DeleteOptions` using the Template API.
+* Filter conditions for lightweight transaction update and delete (`UPDATE … IF <condition>`, `DELETE … IF <condition>`).
 
 [[new-features.2-1-0]]
 == What's new in Spring Data for Apache Cassandra 2.1