Improved tab close message/button.

app/assets/javascripts/app/controllers/_application_controller.js.coffee

@@ -444,6 +444,7 @@ class App.ControllerModal extends App.Controller
       keyboard: true
       close:    true
       head:     '?'
+      buttonClass: 'btn--success'
 
     options = _.extend( defaults, options )
 
@@ -467,6 +468,7 @@ class App.ControllerModal extends App.Controller
       close:        @close
       cancel:       @cancel
       button:       @button
+      buttonClass:  @buttonClass
     ) )
     if @el && !@message && !@detail
       @modalElement.find('.modal-body').html @el

app/assets/javascripts/app/controllers/taskbar_widget.js.coffee

@@ -121,7 +121,8 @@ class Remove extends App.ControllerModal
     @message     = 'Tab has changed, you really want to close it?'
     @cancel      = true
     @close       = true
-    @button   = 'Close'
+    @button      = 'Discared changes'
+    @buttonClass = 'btn--danger'
     @show()
 
   onSubmit: (e) =>

app/assets/javascripts/app/views/modal.jst.eco

@@ -22,7 +22,7 @@
         <a class="subtle-link standalone js-cancel" href="#/"><%- @T( 'Cancel & Go Back' ) %></a>
   <% end %>
   <% if @button: %>
-        <button type="submit" class="btn btn--success js-submit align-right"><%- @T( @button ) %></button>
+        <button type="submit" class="btn <%= @buttonClass %> js-submit align-right"><%- @T( @button ) %></button>
   <% end %>
       </div>
     </div>