* Number of concurrent requests for fetching the application info is
  limited to 15 requests

* Fetching the application info is deferred by 50ms to let the browser
  render the view

* Flattened application/group structure to save inner ng-repeat

* ng-repeat for notification settings and view drop down is executed
  when the popup/dropdown is visible

When the list contains a lots of applications many requests are made for
dynamic views (e.g. heapdump, flyway, logfile, ...). With this commit
the availability check for these views is deferred until the user opens
toggles the dropdown. This should lead to far fewer requests.

fixes #346

Additionally the url list is not anymore overlapped then having a lot of
tabs for the detail views.

fixes #347

After this commit the applications in the overview are grouped by application-
name. In case the search box is used all groups get expanded automatically.
Additionally the info column is now expandable via button and not a pre-section
anymore.

closes #218

This adds a new FilteringNotifier which can use filters to suppres certain
events from being notified of. Two filter implementation are provided, one
filtering by name and one by id. Additional when a FilteringNotifier bean is
present, the autoconfiguration creates a REST-controller to add and remove
filters at runtime.

 - Updated Angular to 1.5.3
 - Removed Angular UI Bootstrap, to make the Angular update possible without
   updating Bootstrap
 - Moved every view into its own module
 - Added concatenation of the module js and css assets to the webserver
 - Created directives/components for the various visual components and trimmed
   down the controllers
 - Removed unecessary ngRoute
 - Removed classpath section in details (it is included in environment)
 - Moved the counters and gauges to a separated metrics view
 - Added target="_blank" for the logfile
 - Added information about version, loaded ui modules to the about page
 - Extracted the activiti view to a separate maven artifact

With this commit it is now possible to add your own ui modules to the servers
classpath and they will show up in the ui.
Every module needs an "entry" script file in the classpath located under
`META-INF/spring-boot-admin-server-ui/<modulename>/module.js`.
The module is be implemented as angular module and needs to be added to
the global `uiModules` list.
The spring-boot-admin-server-ui-activiti module is a simple sample for
adding a application view but it is also possible to add main-views.
Please have a look at the events module in spring-boot-admin-server-ui/modules.

Please note that the internals of the ui can change anytime.

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

This should avoid confusion as in #131

/info and /configprops are from now on only fetched in the overview on first render
and whenever the status of an application changes.

closes #95

But make no use of it.

fixes #96

fixes #107

closes #86

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.

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

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