Date and time format finalization for the exports:

- properly display the date and time as expected in the preview during an interactive export
- differentiate date vs date&time formats in the Excel export
- use the custom format in the default URL provided by the query phrasebook

SVN:trunk[4089]

js/tabularfieldsselector.js

@@ -290,6 +290,7 @@ $(function()
 				$('#'+this.sId+' .preview_header').hide();
 				$('#'+this.sId+' .table_preview').html('<div class="export_empty_preview">'+this.options.labels.empty_preview+'</div>');
 			}
+			$('.form_part:visible').trigger('preview_updated');
 		},
 		_get_field_by_code: function(sFieldCode)
 		{