s-c-commons creates an AutoServiceRegistrationProperties bean if enabled.

This commit only auto registers with eureka if that bean is available.

use `com.netflix.loadbalancer.DummyPing` instead of `NoopPing`

This eliminates the startup of another theadpool.

fixes gh-1504

Don’t add URL protocol when url is set using EL

Uses configuration from IConfigClient reference to always use the most up to date configuration.  Fixes #1481.

Document Eureka client zone config

Defaults were set too late and were overriding values set in the environment.

Specifically, spring.application.name took precedence over eureka.instance.appname.

 fixes gh-1516

Specifically, add `@ConditionalOnBean(EurekaClient.class)`.

Fixes an issue where eureka and ribbon are on the classpath, eureka.client.enabled=false which would cause a bean not found exception.

fixes gh-1511

(cherry picked from commit d1f8c031)

Upgrade Eureka to 1.6.1.  Fixes #1495.

Document how to use thread isolation with hystrix and feign.  Fixes #1191.

Fixes gh-1462

fixes gh-1345

Use the new ServiceRegistry interface

Creates a new EurekaRegistration object that aggregates classes needed
for a single registration.

RxJavaReturnValueHandlerConfig can only be loaded when both spring-web
and spring-webmvc are on the classpath, because it contains a reference
to the WebMvcConfigurerAdapter class.

But the ConditionalOnClass annotation only included the class from
spring-web. In our situation, only spring-web was on the classpath,
resulting in a NoClassDefFoundError for WebMvcConfigurerAdapter. Fix it
by adding that class to the condition as well.

Emphasises that it's a black list, and clarifies that you need to
set it to empty to get authorization and cookie headers.

Document Hystrix Fallback For Zuul

Provide A Retry Policy For Ribbon Clients

-additional refactoring from changes in s-c-commons

Fixes gh-1363

Resolve spring.application.name via property resolver

Breaks Spring Boot 1.3 compatibility, enables 1.5