Dialog: Trigger event when createform fields are being drawn

Trigger new event 'cloudStack.createForm.makeFields'
before field params are being passed to createForm for rendering.

This allows plugins to change and intepret fields before they are drawn.

ui/scripts/ui/dialog.js

@@ -70,6 +70,11 @@
                 return key;
             });
 
+            $(window).trigger('cloudStack.createForm.makeFields', {
+                $form: $form,
+                fields: fields
+            });
+
             var ret = function() {
                 $('.overlay').remove();