DATACASS-529 - Polishing.

Introduce ReactiveResultSet.availableRows() to fetch rows without transparent paging. Refactor QueryUtils to extract a Slice from an Iterable. Add slice(Query, Class) to ReactiveCassandraOperations to expose a consistent API. Convert space indentation to tab indentation. Add tests. Add since tags. Add documentation. Reformat code.

Original pull request: #128.

src/main/asciidoc/new-features.adoc

@@ -11,8 +11,9 @@ This chapter summarizes changes and new features for each release.
 * Cassandra Mapped Tuple support via `@Tuple`.
 * Support for Cassandra `time` columns via `LocalTime`.
 * Support for `map` columns using User-defined/converted types.
-* <<cassandra.mapping-usage.events>>
+* <<cassandra.mapping-usage.events>>.
 * Kotlin extensions for Template API.
+* Reactive Paging support through `Mono<Slice<T>>`.
 
 [[new-features.2-0-0]]
 == What's new in Spring Data for Apache Cassandra 2.0

src/main/asciidoc/reference/cassandra-repositories.adoc

@@ -117,7 +117,7 @@ as the following example does by autowiring `PersonRepository`:
 ====
 [source,java]
 ----
-@RunWith(SpringJUnit4ClassRunner.class)
+@RunWith(SpringRunner.class)
 @ContextConfiguration
 public class PersonRepositoryTests {
 
@@ -139,7 +139,7 @@ Cassandra repositories support paging and sorting for paginated and sorted acces
 ====
 [source,java]
 ----
-@RunWith(SpringJUnit4ClassRunner.class)
+@RunWith(SpringRunner.class)
 @ContextConfiguration
 public class PersonRepositoryTests {
 

src/main/asciidoc/reference/reactive-cassandra-repositories.adoc

@@ -137,6 +137,35 @@ public class PersonRepositoryTests {
 ----
 ====
 
+Cassandra repositories support paging and sorting for paginated and sorted access to the entities. Cassandra paging requires a paging state to forward-only navigate through pages. A `Slice` keeps track of the current paging state and allows for creation of a `Pageable` to request the next page. The following example shows how to set up paging access to `Person` entities:
+
+.Paging access to `Person` entities
+====
+[source,java]
+----
+@RunWith(SpringRunner.class)
+@ContextConfiguration
+public class PersonRepositoryTests {
+
+    @Autowired PersonRepository repository;
+
+    @Test
+    public void readsPagesCorrectly() {
+
+      Mono<Slice<Person>> firstBatch = repository.findAll(CassandraPageRequest.first(10));
+
+      Mono<Slice<Person>> nextBatch = firstBatch.flatMap(it -> repository.findAll(it.nextPageable()));
+
+      // …
+    }
+}
+----
+====
+
+The preceding example creates an application context with Spring's unit test support, which performs annotation-based
+dependency injection into the test class. Inside the test cases (the test methods), we use the repository to query
+the data store. We invoke the repository query method that requests all `Person` instances.
+
 [[cassandra.reactive.repositories.features]]
 == Features