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

The 'use strict' in the activit module affected the global scope and
broke the ui for some orderings of the modules. With this commit the
module is wrapped into a function so the global scope isn't affected.

fixes #294

closes #237

The 1.4.0 release was a total disaster. Webpack didn't build the css correctly
because of travis using an ancient nodejs version.

 - 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.