- fixed the 'options' parameter when calling API functions that support the
parameter and when using the 'success' and/or 'fail' callbacks;
- CSS fix for IE8;
- added support for multiple extra columns, each column can display
data from the 'itemData.props[the_column_property]', the column width
can be set with CSS or from the init options;
- changed .moveUp, .moveDown, .moveFirst and .moveLast, now all use
.setIndex to set item position.