fixes gh-225

It doesn't make sense to @EnableFeignClients in autoconfig
because the user needs to specify a package to scan. It does
make sense (sort of) to set up the encoder/decoder/logger etc.

See gh-226

When the URL is passed down to Ribbon and reconstructed from
a LoadBalancer the Server only knows about host and port, so the scheme
has to come from the original declaration.

There's still a potential problem with Eureka remote services that
are available with a non-secure port as well (probably fairly rare).

Fixes gh-221

Users need to know how to configure and use the Eureka
metadata because it isn't immediately obvious and does
require some decisions to be made.

Fixes gh-102

fixes spring-cloud/spring-cloud-bus/issues/7

fixes gh-201

fixes 208

fixes gh-210

To write file data the message converter needs the file content
to be provided in the form of an HttpEntity per file.

Fixes gh-197 again

fixes gh-204

only update route location if location is empty.  Fixes bug introduced in 18b346de

update the serviceId and location for statically configured routes that are also part of serviceDiscovery.

fixes gh-199

If the ServerProperties contain a servletPath then the handler mapping
does not contain that prefix, but the incoming request URI does. This leads
to some interesting prefix stripping gymnastics. All the existing tests
assumed that the prefix was empty (the default for a Spring boot app).

See gh-199

This reverts commit 29bee28d.

and also allow explicitly configured services to be unignored. I.e.

zuul:
  ignoredServices: *
  routes:
    foo: /foo/**

Will expose only the foo service.

Fixes gh-198

Instead of building a String, if we use an existing
HttpMessageConverter from Spring web, we can support multipart
form data.

Fixes gh-197 (hopefully)

Now that blitz4j 1.36.0 is out, with a bit of hackery we can prevent
it from barfing on startup. Seems worth it (and certainly makes
it easier to embed Eureka server).

Fixes gh-3

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).