closes #86

Added a simple event journal, jorunaling all ClientApplicationEvents using a simple, non-persistent store. So all information is lost after restart. Added corresponding view to UI.

The health-check is made at a fixed interval (default: 10s) for all expired status-information (default-lifetime: 30s).
The application health-endpoint must either respond with a JSON-Body having a status-field or with an empty body and all 2xx-http-responses are interpreted as UP and every other status as DOWN.

closes #69

This allows to (re-)set properties via POST-requests to the environment endpoint.

If an application is changing state while the page is open a desktop notification is shown.

Activiti spring boot starter exposes the /activiti endpoint which is now exposed in the admin ui. See https://spring.io/blog/2015/03/08/getting-started-with-activiti-and-spring-boot for further details on creating a client

Use tabs for idents, small lint fixes

* make sure non-UP applications are shown at the top of the list  (closes #55)
* refinements for health-section
* remove-button for all apps
* fixed headers in details view

closes #35

Altered JSON invocation of JMX methods to support the following change implemented in Jolokia Release 0.91 (http://www.jolokia.org/changes-report.html):

Fixed issue with overloaded methods where one variant takes no arguments. This no-arg variant can be specified with the signature "()" after the operation name.

using Gulp & Browserify
with a little help from https://blog.codecentric.de/en/2014/08/angularjs-browserify