prevents busy conversation exceptions
* file uploads in define samples happen now in a modal dialog, so it is more clear to the user that no other actions can be taken during upload.
  rich:fileUpload-event onUpload does not work, therefore it is not possible to keep the user from closing the dialog. #221
* in evaluate experiments the "please wait" is toggled during evaluation, prevents the user from triggering other actions. #221. fixes #214.