When having registered some applications via discovery and some via http you
can now add the appication names of the non-discovery to the ignored services
so that they won't considered as stale an be removed from the registry by the
ApplicationDiscoveryListener.

fixes #244

With this commit you can specify the management.port for a discovered service
via the metadatamap.

fixes #226

Sometimes Eureka only provides only the securedhealthUrl for the service.
Previous to this commit the applciation won't be registered in that case. So
with this commit the securedHealthUrl from Eureka is used, when available

fixes #224

Checks the DiscoveryClient's services on each heartbeat and removes all
services, which are no longer registered.

Use the metadata for health-/managament-url in the default service conversion.
This allows custom health- and management-path per application.

fixes #205

fixes #205

fixes #209

closes #201

fixes #202

From Spring Cloud Brixton on, the PreDecorationFilter doesn't pass sensitive
headers downstream.
So the ZuulProperties from the ApplicationContext needs to be used (instead
of creating a new instance), so that the properties can be customized.

Update to Spring Cloud Brixton and add the concept of ServiceInstanceConverters.
A ServiceConverter is used to convert discovered ServiceInstances to
Applications. The old converter and one for Eureka is provided. It is also
possible to provide your own implementation.

closes #154

added CompositeNotifier to allow for multiple notifiers. Only used when multiple notifiers are configured and no primary notifier is already configured.

changed HipchatNotifierConfiguration to be a static class, otherwise application context doesn't start up when hipchat notification is enabled.

The RemindingNotifier sends periodic notifications using a delegate. It must be
added explicitly to the ApplicationContext

The polling in the UI is replaced with server side events. Status changes are
now reported immediately from the admin server to the UI.

Cause it was often requested, now the context-path for the admin server is
configurable. This allows to move the admin-ui and endpoints to other http-
paths than "/".
NOTE: I'd still advise not to add the admin to the application you want to
monitor.

Spring Cloud Brixton hasn't been released yet, so to get the Spring Boot Admin
release out. We downgrade to Spring Cloud Angel.SR3.

To not pollute the log with warnings when an app is offline log the exception with
debug when the application status already was offline before the check. So only the
first exception when the state changes to offline will be logged.

closes #125

To not accidentally expose senstive urls only expose whitelisted
management-endpoints via the zuul proxy filter.

Deriving from Spring Clouds ProxyRouteLocator has become too difficult. It would
have required to either set fixed ZuulProperties or providing a DiscoveryClient.
So we are shipping our own lean version of it. Since the PreDecorationFilter is tightly
coupled to the ProxyRouteLocator we also have to use our own stripped down version.

closes #123

Check if the status field is a String and don't propagate any Exception
from the StatusUpdater, so that the application don't fail like in #120

Streamline the Hazelcast support with boot 1.3 and support storing events in hazelcast

closes #113

Due to our use of @Conditionals on our @Configuration-classes the import must be deferred, so that the classes are processed after all other @Configuration-classes