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

If the management.port and server.port is not the same, the current logfile-
endpoint detection fails. With this commit the presence of the endpoint is
determined via a HEAD-request

fixes #165

This commit contains multiple changes:
 - Start the registration task after the ApplicationReady event. This makes
   AdminClientProperties.isReady() unnecessary.
 - The RegistarApplicationListener has two new public methods to start/stop the
   periodic registration task.
 - Add spring.boot.admin.auto-registration property (default: true). When this
   property is set the registration task is automatically scheduled after the
   ApplicationReadyEvent.

closes #151

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

This commit enables the use of // @formatter:off and // @formatter:on
to surround lines of code that should not be formatted.

In case prefer-ip is true and no server.address is set use the IP address from
InetAddress.getLocalHost(); like it is done in Eureka.

When an empty application list was initially returned the events wasn't  pushed
into the applications array, because the Applications.query returned no array.
This issue made a page refresh necessary.

Add spring.boot.admin.client.enabled property to explicitly disable the
spring-boot-admin-client, (e.g. for unit tests). Defaults to true. The client is
active when spring.boot.admin.client.enabled is true and spring.boot.admin.url
is set.

fixes #156

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

Fixed typo

In case you have clustered admin servers, you can now specify multiple urls for
the client to register at. So that in the case the first server is down it will
register at the next one specified in the list. This allows you to do cluster-
ing without the need for a load-balanced host.

closes #137

Remove the git-commit-id-plugin from the sample and don't fail in docs when the
sources are not located in an git-repository (e.g. downloaded from zip)

I did an accidental release of a 1.3.2, so we need another increment

There is a problem with the relaxed binding for system environment variables in
spring boot and ignoreUnknownFields for ConfigurationProperties. So we need to
remove it for now.

fixes #135

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.

For less commits to the gh-pages remove the last-update-label from the footer.
So that a commit is only made if the content changes.

This should avoid confusion as in #131

Take the servlet-path into account when computing the management-/healht-url.
This is not done for the service-url, since the main use-case for setting the
servlet-path is to get the dispatcher-servlet out of the way for other servlets.

fixes #133