Started moving synchronous cluster implementation to asynchronous one. Synchronous is broken on some browsers as soon as one coordinator is dead

Conflicts:
	js/apps/system/aardvark/clusterFrontend/js/views/showClusterView.js
Cluster Servers and Coordinators are now working async. It is now possible to contact a cluster even if some of the coordinators are down
Continued implementing async functionality in cluster dashboard

Conflicts:
	js/apps/system/aardvark/clusterFrontend/js/views/showClusterView.js
Added an upgrade cluster button when cluster is shutdown. And further adoption to asynchronous code

Conflicts:
	js/apps/system/aardvark/clusterFrontend/js/views/clusterDownView.js
If no coordinator is available the interface will tell you. Screen needs to be prettified. Still some issues when interface comes back, null-pointer exceptions
Added unreachable view
Fixed a bug with retrying whenever the connection was lost
Fixed a redircetion bug (Dead Coordinator -> Revive Coordinator -> Dead Coordinator -> Revive Coordinator) did not load cluster interface twice
Fixed cluster dashboard on server failure
Fixed a bug in cluster dashboard, which made it impossible to view the dashboard for a multi machine cluster. #883