The Eureka instance has to provide status page and health check
URLs. We only provide a sensible default if the app is a vanilla
Actuator. This change shows users explicitly how to customize those
settings.

Fixes gh-192

Fixes gh-194

The ProxyRouteLocator now has a retryable property (default
null which means Ribbon will choose the default - usually false).

Fixes gh-115, fixes gh-124

When running from /hystrix or from / (with a forward) the
webjars and the monitor endpoint need to be resolvable, so
we need to use the FTL macros again.

Fixes gh-193

Adds a metadataMap for the Server.zone so that user can
provide the data through external configuration if needed.

Some singleton clashes are inevitable if running multiple
apps i nteh same JVM, but we can at least try and not fall off
a cliff when they happen.

fixes gh-187

Replaces the boolean flag (loadbalance) for switching between service
resolution (by name) or straight URL bashing.

By analogy with @EnableJpaRepositories, so it's obvious that
the same thing will happen (interfaces are turned into concrete
@Beans).

added preferIpAddress section to eureka and updated ribbon docs to show what beans are created by default and how to override them.

 This includes support for: ServerList, ServerListFilter, IRule, IPing and IClientConfig.
 Eliminates custom wrapping of ServerList.

 fixes gh-185

fixes gh-144

update sidecare enabled property, make eureka portion of config conditional on eureka on classpath so other DiscoveryClient impls can use it.

fixes gh-159

fixes gh-179

fixes gh-180

fixes gh-182

Add feign-slf4j support.

fixes gh-178

The main problem here was the ZuulProperties being used everywhere. I also
took the opportunity to thin out the top level zuul package and keep the
web and route locator pieces in sub-packages for readability.

Fixes gh-172

A cleaner separation of ribbon and the eureka-dependent ribbon
configuration is achieved by adding a BeanPostProcessor to do the
ServerList wrapping, instead of doing it for every single ribbon
client.

See gh-172

proxy DiscoveryHeartbeatEvent's from parent to child be publishing a EurekaHeartbeatEvent and having zuul listen for EurekaHeartbeatEvent as well.

fixes gh-171

Fixes gh-153

fixes gh-153

Fixes gh-160

 fixes gh-147

fixes gh-149