Gh 586 loadbalancer starter (#599)

* Add loadbalancer starter. Add property to set BlockingLoadBalancerClient
as default non-reactive loadbalancer. Start working on auto-enabling caching.

* Automatically enable caching. Fixes gh-585.

* Add tests.

* Add reference docs.

* Change property name.

spring-cloud-commons-dependencies/pom.xml

@@ -54,6 +54,11 @@
 				<artifactId>spring-cloud-starter</artifactId>
 				<version>${project.version}</version>
 			</dependency>
+			<dependency>
+				<groupId>org.springframework.cloud</groupId>
+				<artifactId>spring-cloud-starter-loadbalancer</artifactId>
+				<version>${project.version}</version>
+			</dependency>
 		</dependencies>
 	</dependencyManagement>
 	<profiles>