Bug 207120 Please model provide an API for data type conversion.
Currently, there're two data types: column data type and parameter data type. But they're inconsistent. Could model provide APIs for conversion between the two types. Thanks. In addition: please check the code into head and 2.2.1 branch, because we have a 2.2.1 bug to fix.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleUtil.java
*             if the exception occur when interpret the stream data.
	 */
	public static ActionHandle deserializeAction( InputStream streamData )
			throws DesignFileException
	{
		return deserializeAction( streamData, null );
	}
	/**
	 * Deserialize an input stream into an Action.
	 * 
	 * @param streamData
	 *            a stream represent an action.
	 * @param element
	 * @return an internal Action structure
	 * @throws DesignFileException
	 *             if the exception occur when interpret the stream data.
	 */
	public static ActionHandle deserializeAction( InputStream streamData,
			DesignElementHandle element ) throws DesignFileException
	{
		
		
		DesignElement image = new ImageItem( );
		DesignElement e = element == null ? image : element.getElement( );
		ActionParserHandler handler = new ActionParserHandler( image );
		Module module = element == null ? handler.getModule( ) : element
				.getModule( );
		if ( streamData == null )
		{
			Action action = StructureFactory.createAction( );