Re-use NavigationCheck logic

The enterprise switcher now uses the same code as NavigationCheck to
confirm leaving a changed form. This makes FormState obsolete.

Conflicts:
	app/assets/javascripts/admin/enterprises/controllers/enterprise_controller.js.coffee

app/assets/javascripts/admin/utils/services/form_state.js.coffee

@@ -1,3 +0,0 @@
-angular.module('admin.utils').service 'FormState', ->
-#Simple service to share form state across different controllers/scopes
-  { isDirty: false }

app/assets/javascripts/admin/utils/services/navigation_check.js.coffee

@@ -20,13 +20,17 @@ angular.module("admin.utils")
 
       # Action for angular navigation.
       locationChangeStartHandler: ($event) =>
-        message = @getMessage()
-        if message and not $window.confirm(message)
+        if not @confirmLeave()
           $event.stopPropagation() if $event.stopPropagation
           $event.preventDefault() if $event.preventDefault
           $event.cancelBubble = true
           $event.returnValue = false
 
+      # Check if leaving is okay
+      confirmLeave: =>
+        message = @getMessage()
+        !message or $window.confirm(message)
+
       # Runs callback functions to retreive most recently added non-empty message.
       getMessage: ->
         message = null