Bug 136279 Structure and table datatypes should be hidden.
Description: Structure and table datatype should be hidden. Steps to reproduce: In table data binding, I saw structure and table two datatypes. They are not supported now, so they should be removed.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/adapter/ModelDteApiAdapter.java
* @param context2
	 * @return
	 * @throws BirtException
	 */
	private IJointDataSetDesign newJointDataSet( JointDataSetHandle handle, ExecutionContext context2 ) throws BirtException
	{
		Iterator it = handle.joinConditionsIterator( );
		List joinConditions = new ArrayList();
		
		JoinConditionHandle jc = null;
		
		while( it.hasNext( ) )
		{
			jc = (JoinConditionHandle)it.next( );
			joinConditions.add( new JoinCondition( new ScriptExpression( jc.getLeftExpression( )), new ScriptExpression(jc.getRightExpression( )),toDteJoinOperator(jc.getOperator( )))) ;
		}
		
		int joinType = toDteJoinType(jc.getJoinType( ));
		
		IBaseDataSetEventHandler eventHandler = new DataSetScriptExecutor(
				handle, context );
		JointDataSetDesign dteDataSet = new JointDataSetDesign(handle.getName( ), jc.getLeftDataSet( ), jc.getRightDataSet( ), joinType, joinConditions);
		dteDataSet.setEventHandler( eventHandler );
		
		adaptBaseDataSet( handle, dteDataSet );
		return dteDataSet;
	}
	private int toDteJoinOperator( String operator )
	{
		if( operator.equals( DesignChoiceConstants.JOIN_OPERATOR_EQALS ))